  United States Court of Appeals
      for the Federal Circuit
                ______________________

                  SUNPREME INC.,
                  Plaintiff-Appellant

                           v.

UNITED STATES, SOLARWORLD AMERICAS, INC.,
          Defendants-Cross-Appellants
            ______________________

            2018-1116, 2018-1117, 2018-1118
                ______________________

   Appeals from the United States Court of International
Trade in No. 1:16-cv-00171-CRK, Judge Claire R. Kelly.
                 ______________________

               Decided: January 7, 2020
                ______________________

    JOHN M. GURLEY, Arent Fox, LLP, Washington, DC, for
plaintiff-appellant. Also represented by DIANA DIMITRIUC
QUAIA, NANCY NOONAN.

    JUSTIN REINHART MILLER, International Trade Field
Office, Commercial Litigation Branch, Civil Division,
United States Department of Justice, New York, NY, for
defendant-cross-appellant United States. Also represented
by REGINALD THOMAS BLADES, JR., JEANNE DAVIDSON,
JOSEPH H. HUNT, Washington, DC; MERCEDES MORNO,
United States Department of Commerce, Washington, DC.

   TIMOTHY C. BRIGHTBILL, Wiley Rein, LLP, Washington,
2                           SUNPREME INC. v. UNITED STATES




DC, for defendant-cross-appellant SolarWorld Americas,
Inc. Also represented by TESSA V. CAPELOTO, LAURA EL-
SABAAWI, USHA NEELAKANTAN, MAUREEN E. THORSON.
                ______________________

  Before PROST, Chief Judge, NEWMAN, LOURIE, DYK,
MOORE, O’MALLEY, REYNA, TARANTO, CHEN, HUGHES, and
               STOLL, Circuit Judges. ∗
Opinion for the court filed by Chief Judge PROST, in which
Circuit Judges NEWMAN, LOURIE, DYK, MOORE, O’MALLEY,
    REYNA, TARANTO, CHEN, HUGHES, and STOLL, join.
PROST, Chief Judge.
     Sunpreme Inc. appeals from the final decision of the
United States Court of International Trade in favor of the
United States and SolarWorld Americas, Inc., concluding
that Sunpreme’s solar modules are covered by the scope of
antidumping and countervailing duty orders on U.S. im-
ports of certain solar cells from the People’s Republic of
China. The United States and SolarWorld cross-appeal
from the same decision, which also concluded that the
United States Department of Commerce (“Commerce”)
could not instruct United States Customs and Border Pro-
tection (“Customs”) to continue suspending liquidation of
Sunpreme’s solar modules entered or withdrawn from
warehouse for consumption before the scope inquiry was
initiated.
     A unanimous panel of this court previously affirmed
the portion of the Court of International Trade’s decision
upholding Commerce’s scope ruling. Sunpreme Inc. v.
United States, 924 F.3d 1198, 1212 (Fed. Cir. 2019) (“Panel
Opinion”). A majority of that panel, addressing the cross-
appeal brought by the United States and SolarWorld, also
affirmed the Court of International Trade’s conclusion that


    ∗   Circuit Judge Wallach did not participate.
SUNPREME INC. v. UNITED STATES                            3



Commerce’s instructions to continue suspending liquida-
tion of goods entered or withdrawn prior to the scope in-
quiry were unlawful. Id. at 1215.
    The United States petitioned for en banc rehearing of
its cross-appeal. We now grant that petition to resolve
whether it is within Customs’s authority to preliminarily
suspend liquidation of goods based on an ambiguous anti-
dumping or countervailing duty order, such that the sus-
pension may be continued following a scope inquiry by
Commerce. We conclude that it is.
    Because we find that Commerce’s instructions regard-
ing continued suspension of liquidation were lawful and
not reliant on ultra vires acts of Customs, we grant rehear-
ing en banc limited to that issue, vacate the original panel
opinion, and reverse that portion of the Court of Interna-
tional Trade’s decision. Commerce’s instructions are rein-
stated in full.
    Although the original panel opinion is vacated due to
our en banc consideration of the United States’s cross-ap-
peal, we reinstate the remaining portions of the panel opin-
ion, including the affirmance of the Court of International
Trade’s conclusion that Commerce’s final scope ruling is
supported by substantial evidence. For the sake of com-
pleteness, the undisturbed portions of the panel opinion
are reproduced below. 1
                       BACKGROUND
                             I
    Solar modules convert sunlight into electricity. Many
solar modules are composed of crystalline silicon photovol-
taic (“CSPV”) cells. Those modules contain crystalline sili-
con wafers that are processed in the presence of other


   1    Therefore, the en banc portion of this opinion con-
sists only of Part II of the Discussion section.
4                            SUNPREME INC. v. UNITED STATES




chemicals so that one portion of the wafer has a negative
charge (i.e., an n-type layer with excess electrons) and an-
other portion has a positive charge (i.e., a p-type layer with
excess electron holes). The existence of the positive and
negative layers in a single wafer creates what is known in
the industry as a “p/n junction.” J.A. 325, 466, 546, 2719.
A built-in electric field is created at and around the site of
the p/n junction due to the electric charge differential.
When sunlight strikes a CSPV cell, the light energy is ab-
sorbed, free electrons in the n-type layer attempt to unite
with holes in the p-type layer at and around the p/n junc-
tion, and the resulting energy generated by the mobilized
electrons is translated into usable electricity.
     Other solar modules are composed of thin films. Those
modules contain very slim layers of semiconductor mate-
rial, such as amorphous silicon, deposited on a substrate of
some sort, such as glass, stainless steel, or plastic. Some of
the layers are doped with chemicals that create an excess
of electron-donating impurities (i.e., n-type layers), while
other layers are doped with chemicals that create an excess
of hole-donating impurities (i.e., p-type layers). When the
n-type and p-type layers are put in contact, they form a p/n
junction, and a built-in electric field is created. The impo-
sition of an additional semiconductor substrate (i.e., intrin-
sic layer) between the doped thin film layers forms what is
known as a “p/i/n junction.” J.A. 531, 546. With respect to
p/i/n junctions, the electric field extends across the entire
intrinsic region.
    In 2011, SolarWorld filed a petition with Commerce
and the United States International Trade Commission
(“ITC”) seeking the imposition of antidumping and coun-
tervailing duties on CSPV cells imported from the People’s
Republic of China, pursuant to §§ 701 and 731 of the Tariff
Act of 1930. In 2012, following an investigation, Commerce
issued antidumping and countervailing duty orders cover-
ing those imports. Crystalline Silicon Photovoltaic Cells,
Whether or Not Assembled Into Modules, From the People’s
SUNPREME INC. v. UNITED STATES                              5



Republic of China: Countervailing Duty Order (“CVD Or-
der”), 77 Fed. Reg. 73,017 (Dec. 7, 2012); Crystalline Silicon
Photovoltaic Cells, Whether or Not Assembled Into Mod-
ules, From the People’s Republic of China: Amended Final
Determination of Sales at Less Than Fair Value, and Anti-
dumping Duty Order (“AD Order”), 77 Fed. Reg. 73,018
(Dec. 7, 2012). Both orders recite the same scope, which
reads in relevant part as follows:
    The merchandise covered by this order is crystal-
    line silicon photovoltaic cells, and modules, lami-
    nates, and panels, consisting of crystalline silicon
    photovoltaic cells, whether or not partially or fully
    assembled into other products, including, but not
    limited to, modules, laminates, panels and building
    integrated materials.
    This order covers crystalline silicon photovoltaic
    cells of thickness equal to or greater than 20 mi-
    crometers, having a p/n junction formed by any
    means, whether or not the cell has undergone other
    processing, including, but not limited to, cleaning,
    etching, coating, and/or addition of materials (in-
    cluding, but not limited to, metallization and con-
    ductor patterns) to collect and forward the
    electricity that is generated by the cell.
                            ....
    Excluded from the scope of this order are thin film
    photovoltaic products produced from amorphous
    silicon (a-Si), cadmium telluride (CdTe), or copper
    indium gallium selenide (CIGS).
CVD Order, 77 Fed. Reg. at 73,017; AD Order, 77 Fed. Reg.
at 73,018–19. Commerce notified Customs of the AD and
CVD Orders (“the Orders”) and required cash deposits or
posting of a bond equal to the appropriate rate in effect at
the time of entry for covered imports.
6                           SUNPREME INC. v. UNITED STATES




     Sunpreme manufactures solar modules in China.
Those modules contain bifacial solar cells that are com-
posed of thin films, which are several layers of amorphous
silicon less than one micron thick, deposited on both sides
of a crystalline silicon wafer. Following publication of the
Orders on December 2, 2012, Sunpreme entered its mer-
chandise as entry type “01,” meaning not subject to the Or-
ders, and continued to do so without question from
Customs until early 2015, when, for unknown reasons,
Customs began to question whether Sunpreme’s entries
were covered by the Orders. Initially unsure whether the
Orders covered Sunpreme’s entries, Customs sought advice
from one of its laboratories. On April 20, 2015, Customs
notified Sunpreme that it had decided that Sunpreme’s en-
tries are covered by the Orders, thus resulting in the sus-
pension of liquidation of Sunpreme’s entries and the
requirement that Sunpreme pay cash deposits in order for
its shipments to be released from the port’s warehouse.
Although it objected to Customs’ determination, Sunpreme
complied.
    Meanwhile, Customs continued to question whether
Sunpreme’s solar modules unambiguously fell within the
scope of the Orders. On June 3, 2015, Customs contacted
Commerce seeking guidance on whether Sunpreme’s prod-
ucts were covered by the Orders. Commerce answered that
    a determination as to whether this product is cov-
    ered by antidumping duty order A–570–979 and
    countervailing duty order C–570–980 [i.e., the Or-
    ders] would need to be made by the Department of
    Commerce in a scope ruling which can be requested
    by the importer or exporter.
Sunpreme Inc. v. United States (“Sunpreme I CIT”), 190
F. Supp. 3d 1185, 1191–92, 1199 (Ct. Int’l Trade 2016).
    In a separate proceeding, Sunpreme filed a complaint
with the United States Court of International Trade
(“CIT”) under 28 U.S.C. § 1581(i), directly challenging
SUNPREME INC. v. UNITED STATES                             7



Customs’ determination that Sunpreme’s solar modules
are subject to the Orders. Sunpreme Inc. v. United States
(“Sunpreme I PI”), 145 F. Supp. 3d 1271, 1282 (Ct. Int’l
Trade 2016) (opinion granting preliminary injunction). In
its final decision, the CIT found it undisputed that Sun-
preme’s solar modules contain layers of thin film, but that
Customs’ laboratory tests confirmed those modules also
contain crystalline silicon. Sunpreme I CIT, 190 F. Supp.
3d at 1191, 1195–96. The CIT noted that, although the Or-
ders expressly include “crystalline silicon photovoltaic
cells” within their scope and expressly exclude “thin film
photovoltaic products” from their scope, the Orders do not
define the term thin film products. Id. at 1190, 1195, 1200.
That led the CIT to characterize the scope language in the
Orders as ambiguous with respect to Sunpreme’s solar
modules. Id. at 1203. The CIT concluded, based on our de-
cisions in AMS Associates, Inc. v. United States, 737 F.3d
1338 (Fed. Cir. 2013), and Xerox Corp. v. United States, 289
F.3d 792 (Fed. Cir. 2002), that Customs lacked authority to
interpret the scope of Commerce’s ambiguous Orders, and
thus Customs could not determine that Sunpreme’s solar
modules are subject to those duty orders. Sunpreme I CIT,
190 F. Supp. 3d at 1202–04; accord Sunpreme I PI, 145
F. Supp. 3d at 1283–92. We reversed on appeal because,
under the circumstances presented, the CIT lacked juris-
diction under 28 U.S.C. § 1581(i) to entertain direct chal-
lenges to Customs’ decision given that an alternative
administrative remedy was available. See Sunpreme, Inc.
v. United States (“Sunpreme I”), 892 F.3d 1186, 1192–94
(Fed. Cir. 2018) (“Section 1581(i) ‘may not be invoked when
jurisdiction under another subsection of § 1581 is or could
have been available, unless the remedy provided under
that other subsection would be manifestly inadequate.’”
(quoting Int’l Custom Prods., Inc. v. United States, 467 F.3d
1324, 1327 (Fed. Cir. 2006))). That remedy was a scope
ruling from Commerce interpreting the scope of the duty
orders. Id.
8                            SUNPREME INC. v. UNITED STATES




                             II
                             A
    On November 16, 2015, Sunpreme petitioned Com-
merce for a scope ruling to determine whether its solar
modules are subject to the Orders. Sunpreme contended
that the Orders do not cover its solar modules because they
do not contain CSPV cells, they do not have a p/n junction,
and they otherwise qualify for the Orders’ exclusion be-
cause they are thin film products. On December 30, 2015,
Commerce initiated a formal scope inquiry.
                             B
    After the scope inquiry was initiated, but before a final
ruling was made, Commerce issued a scope ruling in a sep-
arate proceeding deciding that Silveo, Inc.’s Triex photovol-
taic cells are subject to the Orders. Like Sunpreme’s solar
modules, the Triex cells also contain a crystalline silicon
substrate sandwiched between layers of amorphous silicon
thin films.
     Commerce’s regulations at 19 C.F.R. § 351.225(k) es-
tablish its analytical path for deciding whether certain im-
ports are covered by the scope of an antidumping or
countervailing duty order. See Shenyang Yuanda Alumi-
num Indus. Eng’g Co. v. United States, 776 F.3d 1351, 1354
(Fed. Cir. 2015). Commerce first examines the sources
listed under § 351.225(k)(1), which include “the scope lan-
guage contained in the order itself, the descriptions con-
tained in the petition, and how the scope was defined in the
investigation and in the determinations issued by Com-
merce and the ITC.” Id. Those are known as the (k)(1)
sources. If those sources are not sufficient to decide the
matter, then Commerce turns to examining the sources
listed under § 351.225(k)(2), which include the product’s
physical characteristics, ultimate purchasers’ expecta-
tions, the ultimate use of the product, trade channels in
which the product is sold, and the manner in which the
SUNPREME INC. v. UNITED STATES                               9



product is advertised and displayed. Id. Those are known
as the (k)(2) sources.
     Commerce determined that the (k)(1) sources were not
dispositive as to whether the Triex cells fell within the
scope of the Orders. It said the language of the Orders was
ambiguous and the other sources did not resolve whether
p/i/n junctions qualify as p/n junctions or whether products
containing both thin films and crystalline silicon compo-
nents qualify for the thin film exclusion. Commerce cor-
rectly concluded that the hybrid Triex cells “are neither
dispositively covered nor clearly excluded from the scope of
the Orders.” J.A. 884.
    Commerce then concluded that, based on (k)(2) sources,
the Triex cells are covered by the Orders. It said the Triex
cells contain a p/n junction formed by any means because
“a p/i/n junction is simply a type of p/n junction” in which
the electric field is extended over a wider region of the cell.
J.A. 870–71 (internal quotation marks omitted). It con-
cluded the presence of an intrinsic layer does not change
the function of the p/n junction. Moreover, Commerce ex-
plained that conventional thin film cells were designed to
avoid the use of crystalline silicon, and thus allowing prod-
ucts using crystalline silicon as an active, energy-produc-
ing component to qualify for the thin film exclusion “would
result in a physical description that would easily permit
circumvention of the scope of the Orders.” J.A. 871–72.
    Commerce placed the Triex scope ruling on the record
in the Sunpreme proceeding so that interested parties
could comment on any relevant distinctions between Sun-
preme’s solar modules and the Triex product.
                              C
    In July 2016, Commerce issued its final scope ruling
with respect to Sunpreme’s solar modules. Like the Triex
hybrid cells, Commerce understood that Sunpreme’s solar
modules were neither covered nor clearly excluded by the
10                            SUNPREME INC. v. UNITED STATES




descriptions contained in the Orders. Based solely on (k)(1)
sources, it concluded that Sunpreme’s hybrid bifacial thin
film cells are subject to the Orders. It concluded that Sun-
preme’s solar modules contain CSPV cells because they ac-
tively rely on crystalline silicon wafers to generate
electricity and absorb sunlight, just like the crystalline sil-
icon component in the Triex product. It also determined
that the CSPV cells, which include all the active, energy-
generating components such as the thin films and crystal-
line silicon wafers, are at least twenty micrometers thick.
Furthermore, Commerce decided that Sunpreme’s solar
modules contain a p/n junction because, as it said in the
Triex scope ruling, a p/i/n junction is just a form of p/n junc-
tion that does not change the function or nature of the p/n
junction in the CSPV cell. Finally, it concluded that Sun-
preme’s solar modules do not qualify for the thin film ex-
clusion because, as it said in the Triex scope ruling, the
mere presence of some thin film layers does not override
the significance of the crystalline silicon wafer and thus
cannot thereby circumvent the Orders.
     Commerce then issued instructions to Customs order-
ing it to continue suspending liquidation of Sunpreme’s so-
lar modules imported pre-scope inquiry and to begin
suspending liquidation and collecting cash deposits at the
applicable rate for any relevant products Sunpreme en-
tered or withdrew from warehouse for consumption on or
after December 30, 2015. That date is when Commerce in-
itiated the scope proceedings.
                               D
    Sunpreme filed a complaint in the CIT challenging
Commerce’s final scope ruling and its instructions to Cus-
toms. It argued that Commerce’s final scope ruling is un-
supported by substantial evidence and that its instructions
to Customs should not have applied retroactively to solar
modules entered before the scope inquiry was initiated.
The CIT upheld Commerce’s final scope ruling as in
SUNPREME INC. v. UNITED STATES                            11



accordance with law and supported by substantial evi-
dence, but it invalidated as contrary to law that part of
Commerce’s instructions to Customs ordering continued
suspension of liquidation for entries pre-dating the initia-
tion of the scope inquiry. Sunpreme Inc. v. United States
(“Sunpreme II CIT”), 256 F. Supp. 3d 1265, 1278, 1292,
1294 (Ct. Int’l Trade 2017).
    With respect to the final scope ruling, the CIT ex-
plained that substantial evidence supports each of Com-
merce’s four main determinations: that Sunpreme’s solar
modules contain CSPV cells, are at least twenty microme-
ters thick, have a p/n junction, and do not qualify for the
thin film exclusion. Id. at 1278–91. It agreed that the Or-
ders, the petition, the initial investigation, and the Triex
scope ruling provided evidentiary support for Commerce’s
decision. Id.
     With respect to Commerce’s instructions to Customs,
however, it held that it was unlawful for Commerce to or-
der continued suspension of liquidation and collection of
cash deposits for entries made before the scope inquiry was
initiated. Id. at 1291–94. The CIT held that Customs’ sus-
pension of liquidation was ultra vires because Customs
made its decision before the Sunpreme scope inquiry was
completed, at which time Customs lacked authority to in-
terpret the Orders to determine whether Sunpreme’s solar
modules fell within the scope of those Orders. Id. The CIT
again relied on AMS, 737 F.3d 1338, and Xerox, 289 F.3d
792, to support its judgment that Customs lacked authority
to interpret the Orders for suspension of liquidation pur-
poses. Id. at 1292. The CIT therefore concluded that “Com-
merce could not extend the suspension of liquidation on
entries that were not appropriately administratively sus-
pended.” Id. at 1293. It held that Commerce only has au-
thority to “continue” a lawful suspension of liquidation. Id.
   Sunpreme now appeals the CIT’s decision upholding
Commerce’s scope ruling.   The United States and
12                           SUNPREME INC. v. UNITED STATES




SolarWorld cross-appeal the CIT’s partial invalidation of
Commerce’s instruction to Customs to the extent that it di-
rected suspension of liquidation pre-dating the initiation of
the scope inquiry. We have jurisdiction to decide the ap-
peals under 28 U.S.C. § 1295(a)(5).
                        DISCUSSION
     We review CIT decisions de novo and apply anew the
same standard it used. Ad Hoc Shrimp Trade Action
Comm. v. United States, 802 F.3d 1339, 1348 (Fed. Cir.
2015); Atl. Sugar, Ltd. v. U.S., 744 F.2d 1556, 1559 n.10
(Fed. Cir. 1984). Under that standard, we “must uphold
Commerce’s determinations unless they are ‘unsupported
by substantial evidence on the record, or otherwise not in
accordance with law.’” Ad Hoc Shrimp, 802 F.3d at 1348
(quoting 19 U.S.C. § 1516a(b)(1)(B)(i)). While our review
repeats much of the work of the CIT, we do not ignore the
CIT’s informed judgment. Id. Moreover, we give substan-
tial deference to Commerce’s interpretation of its own duty
orders “because the meaning and scope of [those] orders are
issues ‘particularly within the expertise’ and ‘special com-
petence’ of Commerce.” King Supply Co. v. United States,
674 F.3d 1343, 1348 (Fed. Cir. 2012) (quoting Sandvik Steel
Co. v. United States, 164 F.3d 596, 600 (Fed. Cir. 1998)).
    A decision is supported by substantial evidence if the
evidence amounts to “more than a mere scintilla” and “a
‘reasonable mind might accept [it] as adequate to support
a conclusion.’” Ad Hoc Shrimp, 802 F.3d at 1348 (quoting
Consol. Edison Co. of N.Y. v. NLRB, 305 U.S. 197, 217
(1938)). Commerce’s findings “may still be supported by
substantial evidence even if two inconsistent conclusions
can be drawn from the evidence.” Id.
    Two main issues are presented for our review. First,
Sunpreme argues that Commerce’s determination that its
solar modules are covered by the scope of the Orders is not
supported by substantial evidence. Second, the United
States and SolarWorld contend that Commerce’s
SUNPREME INC. v. UNITED STATES                              13



instructions to Customs were not unlawful and should
have been upheld in all respects. We address those issues
in turn below.
                              I
    Sunpreme’s only challenge on appeal is that the CIT
incorrectly concluded that Commerce’s decision that Sun-
preme’s solar modules are covered by the Orders is sup-
ported by substantial evidence. The United States and
SolarWorld disagree.
     Commerce issues scope rulings to clarify the scope of
its antidumping and countervailing duty orders. 19 C.F.R.
§ 351.225(a). As noted above, the analysis for Commerce’s
scope rulings is governed by its regulations at 19 C.F.R.
§ 351.225. “Commerce must first examine the language of
the final order.” Mid Continent Nail Corp. v. United States,
725 F.3d 1295, 1302 (Fed. Cir. 2013). If the language is
unclear, then Commerce must turn to available (k)(1)
sources, including the petition, the initial investigation,
and any earlier determinations by Commerce and the ITC.
Id.; 19 C.F.R. § 351.225(k)(1). If the matter remains unre-
solved, Commerce must turn to available (k)(2) sources, in-
cluding the product’s physical characteristics, ultimate
purchasers’ expectations, the product’s ultimate use, the
channels of trade in which the product is sold, and the way
the product is marketed. Mid Continent, 725 F.3d at 1302;
19 C.F.R. § 351.225(k)(2).
    While “review of the petition and the investigation may
provide valuable guidance as to the interpretation of the
final order,” those sources “cannot substitute for language
in the order itself.” Duferco Steel, Inc. v. United States, 296
F.3d 1087, 1097 (Fed. Cir. 2002). The scope of an order can
encompass certain “merchandise only if [the order] con-
tain[s] language that specifically includes the subject mer-
chandise or may be reasonably interpreted to include it.”
Id. at 1089. Similarly, “merchandise facially covered by an
order may not be excluded from the scope of the order
14                          SUNPREME INC. v. UNITED STATES




unless the order can reasonably be interpreted so as to ex-
clude it.” Mid Continent, 725 F.3d at 1301 (emphasis omit-
ted). At bottom, while Commerce has “substantial freedom
to interpret and clarify its antidumping [and countervail-
ing duty] orders,” it may not do so in a way that changes
them. Id. at 1300 (quoting Novosteel SA v. United States,
284 F.3d 1261, 1269 (Fed. Cir. 2002)).
    Sunpreme attacks all four parts of Commerce’s scope
determination. First, it argues its solar modules are not
CSPV cells. Second, it contends they are far less than
twenty micrometers thick. Third, it asserts they do not
contain a p/n junction. Last, it argues they qualify for the
Orders’ thin film exclusion. Because none of Sunpreme’s
arguments is persuasive, we conclude, as the CIT did, that
Commerce’s final scope ruling is supported by substantial
evidence.
                             A
    Sunpreme argues that substantial evidence does not
support Commerce’s conclusion that its solar modules con-
tain CSPV cells. It argues that Commerce’s decision to
treat any product relying on crystalline silicon to generate
electricity as a CSPV cell is contrary to law because it in-
troduces criteria into the scope of the Orders that are not
covered by their plain language or any (k)(1) sources.
Moreover, it contends that Commerce was wrong when it
stated that the crystalline silicon wafers in Sunpreme’s so-
lar modules play a primary role in the modules’ generation
of electricity. Finally, Sunpreme asserts that its crystal-
line silicon wafers are not doped and thus can produce no
more electricity than a sliver of river rock.
    The United States and SolarWorld respond that Com-
merce correctly concluded that Sunpreme’s solar modules
contain CSPV cells. They identify record evidence they al-
lege shows that Sunpreme’s solar modules contain a doped
crystalline silicon substrate that serves a primary role in
absorbing sunlight, which according to the Triex scope
SUNPREME INC. v. UNITED STATES                               15



ruling is enough to conclude that those modules contain
CSPV cells. They argue Sunpreme simply wishes for us to
reweigh the evidence and reach a different conclusion.
     We agree with the United States and SolarWorld that
substantial evidence supports Commerce’s conclusion that
Sunpreme’s solar modules contain CSPV cells. Commerce
determined that a CSPV cell is a solar product that relies
on crystalline silicon to generate electricity. That is a rea-
sonable interpretation of the Orders based on their plain
language and (k)(1) sources. The Orders expressly cover
“crystalline silicon photovoltaic cells” without much rele-
vant further limitation. CVD Order, 77 Fed. Reg. at
73,017; AD Order, 77 Fed. Reg. at 73,018. The petition
states that “CSPV cells . . . are made from crystalline sili-
con” and “convert the energy of sunlight directly into elec-
tricity, by the photovoltaic effect.”       J.A. 237.     And
Commerce determined in the Triex scope ruling that the
basic purpose of solar cells as opposed to blank crystalline
silicon wafers is electricity generation, and thus a crystal-
line silicon substrate that contributes to energy generation
when the device is struck by sunlight constitutes a CSPV
cell.
     The record supports Commerce’s decision that Sun-
preme’s solar modules rely on crystalline silicon in the elec-
tricity generation process. In the Triex scope ruling,
Commerce explained that traditional CSPV cells contain a
“semi-conduction and photon collection region . . . between
the positively and negatively doped layers of the wafer it-
self,” and that the crystalline silicon wafer in the Triex cells
serves the same purpose because “the wafer is part of the
‘circuit’ between the p/n layers of thin film, creating a re-
gion of semi-conduction and photon collection between the
thin film layers.” J.A. 871. In both instances, the wafer
contributes to “electricity generation between the posi-
tively and negatively doped regions of the cell.” J.A. 871.
It is active because it is slightly doped and plays a critical
role in the energy-generating function of the cells.
16                           SUNPREME INC. v. UNITED STATES




    The same is true for Sunpreme’s solar modules. Sun-
preme said that “the role of the wafer substrate [in its solar
modules] is primarily to provide a light absorbing material
and a stable mechanical/thermal interface for the amor-
phous silicon cells.” J.A. 4575. It also admitted that its
crystalline silicon wafers are naturally slightly doped,
meaning they have a slight inherent p-type or n-type ori-
entation. J.A. 4574, 4773. And Sunpreme has not identi-
fied any evidence that, given those characteristics, the
crystalline silicon wafers in its solar modules do not oper-
ate just like the wafers in the Triex cells, which formed part
of the energy-generating circuit by “creating a region of
semi-conduction and photon collection between the thin
film layers.” It was thus reasonable for Commerce to con-
clude that Sunpreme’s solar modules contain CSPV cells
because the active crystalline silicon wafers in those prod-
ucts absorb sunlight, are slightly doped, and largely serve
the same function as the crystalline silicon in traditional
CSPV cells.
    We are not persuaded by Sunpreme’s arguments to the
contrary. Commerce’s determination that CSPV cells are
those that rely on crystalline silicon to generate electricity
does not add a new criterion to the scope of the Orders be-
cause the scope language can reasonably bear, and the
(k)(1) sources reasonably support, Commerce’s interpreta-
tion. Whether the crystalline silicon wafer is doped or acts
as a primary solar absorber are not new criteria, but in-
stead serve as exemplary guideposts for identifying the
purpose and function of the wafer, which is to contribute to
the generation of energy in the modules. Additionally,
even if the crystalline silicon wafers in Sunpreme’s solar
modules are not the primary solar absorbers in the cells,
Commerce could have reasonably concluded that it is
enough that the wafers provide for and are primarily used
for absorbing sunlight. Finally, while Sunpreme would
have everyone believe that its crystalline silicon wafers are
inert, useless slivers of river rock that play no role in the
SUNPREME INC. v. UNITED STATES                               17



energy-production process, the wafers are naturally
slightly doped and, when used in conjunction with the rest
of the solar module’s components, play a critical role in the
generation of energy. J.A. 245–55, 304–06, 325–27, 871.
We therefore agree with the CIT that substantial evidence
supports Commerce’s conclusion that Sunpreme’s solar
modules contain CSPV cells.
                               B
    Sunpreme argues that its solar modules do not contain
cells that are at least twenty micrometers thick. It argues
the thin film layers are far less than twenty micrometers
thick and the much thicker crystalline silicon substrate
must be excluded from the calculation given that it is not
an active part of the devices. Because we uphold Com-
merce’s conclusion that the crystalline silicon wafer in Sun-
preme’s solar modules are indeed an active part of those
devices, Sunpreme’s thickness argument necessarily fails.
We agree with the CIT that Commerce’s ruling that Sun-
preme’s solar modules have cells that are at least twenty
micrometers thick is supported by substantial evidence.
                               C
     Sunpreme also argues that substantial evidence does
not support Commerce’s conclusion that its solar modules
have a p/n junction. It contends that the term “p/n junc-
tion” as used in the Orders does not require interpretation
because it unambiguously refers to p-type layers directly
adjacent to or abutting n-type layers formed within the
crystalline silicon wafer itself. It asserts that its solar mod-
ules do not have a p/n junction because the thin films form
p/i and i/n junctions outside the wafer substrate and a p/i/n
junction is not a p/n junction.
    The United States and SolarWorld counter that Com-
merce correctly concluded that Sunpreme’s solar modules
contain a p/n junction. They argue that the Triex scope
ruling is a (k)(1) source that supports treating p/i/n
18                           SUNPREME INC. v. UNITED STATES




junctions as a subset of p/n junctions, and that the form of
junction should not be elevated over its function. They also
contend that neither the plain language of the Orders nor
any (k)(1) sources limits the location of the p/n junction to
inside the crystalline silicon component.
    We agree with the United States and SolarWorld that
substantial evidence supports Commerce’s conclusion that
Sunpreme’s solar modules contain a p/n junction. The lan-
guage of the Orders, as well as several (k)(1) sources, sup-
port Commerce’s determination that a p/i/n junction is a
type of p/n junction because the function and nature of the
junction, which is the formation of an electric field, is un-
changed by introducing an intrinsic crystalline silicon
layer between positive and negative thin films. The Orders
provide that covered merchandise must contain “a p/n junc-
tion formed by any means . . . .” CVD Order, 77 Fed. Reg.
at 73,017; AD Order, 77 Fed. Reg. 73,018. Their express
language in no way limits the location, form, or method of
production of the p/n junction.
     The original petition describes the p/n junction as “an
interface of a p-type semiconductor and an n-type semicon-
ductor that is usually formed by dopant additions to create
an intrinsic or extrinsic charge state.” J.A. 237–38. It
states the junction could be heterogenous with various sec-
tions of the substrate responding differently to sunlight,
homogenous, or patterned. J.A. 238. It also notes that the
p/n junction could be formed by several means and recites
a non-exhaustive list that includes dopant diffusion, ion
implanation, epitaxial growth, and bonding of dissimilar
materials. J.A. 238 n.14. SolarWorld later revised its pe-
tition to state that the duty orders cover cells “having a p/n
junction formed by any means,” without reference to a spe-
cific list of possible formation methods. J.A. 816. Solar-
World explained that its change was meant to clarify that
the p/n junction could be formed in any number of ways and
at any one of numerous points in the manufacturing pro-
cess of the cells. Again, like the language of the Orders,
SUNPREME INC. v. UNITED STATES                              19



the petition does not limit the location, form, or method of
production of the p/n junction.
     The Triex scope ruling states that a p/i/n junction
simply is a type of p/n junction because it is one of many
possible means of forming the necessary electric field. That
is, the intrinsic crystalline silicon substrate connects the p-
type and n-type thin film layers so that the cell functions
in the same way as p/n junctions formed by other means.
The intrinsic layer just “‘extends the electric field over a
wider region of the cell’ (i.e., the crystalline silicon wafer
region . . .).” J.A. 871 (citation omitted). Additionally, in
the Triex scope ruling, Commerce soundly and logically re-
jected the argument that the crystalline wafer is inert and
thus plays no role in the electricity generation process be-
cause, if that were true, the substrate could be replaced
with less expensive material than crystalline silicon that
would clearly fall outside the scope of the Orders. There-
fore, the language of the Orders and the (k)(1) sources sup-
port Commerce’s interpretation.
    Here, Sunpreme’s solar modules contain a p/i/n junc-
tion formed by p-type and n-type thin films sandwiched
atop both sides of an intrinsic crystalline silicon wafer.
Substantial evidence therefore supports Commerce’s con-
clusion that Sunpreme’s solar modules contain a p/n junc-
tion, which encompasses p/i/n junctions.
    Sunpreme’s arguments to the contrary do not convince
us otherwise. First, the term “p/n junction” is not unam-
biguously defined in the Orders. The petition’s use of the
word “interface” to describe the boundary between the p-
type and n-type layers that creates the p/n junction does
not necessarily mean that the layers must be in direct con-
tact without the presence of an intervening intrinsic layer.
CVD Order, 77 Fed. Reg. at 73,017; AD Order, 77 Fed. Reg.
at 73,018. Additionally, the fact that glossaries define both
p/n and p/i/n junctions does not mean that the two are mu-
tually exclusive, for the same reason that a dictionary’s
20                            SUNPREME INC. v. UNITED STATES




separate definitions for flower and tulip do not connote ab-
solute distinctiveness.
     Second, Sunpreme is incorrect in its insistence that the
p/n junction must be located within the crystalline silicon
wafer itself. Neither the language of the Orders nor any
(k)(1) source limits the location of the p/n junction, and
Commerce expressly rejected the same argument in its ear-
lier Triex scope ruling. The fact that the petition originally
included a list of means that was later removed is unhelp-
ful to Sunpreme’s argument because the removal broadens
the methods of formation that previously were delineated
in a non-exhaustive list. Furthermore, a SolarWorld rep-
resentative’s statement during the ITC conference that the
p/n junction is created within the silicon base material does
not conflict with a junction formed by p-type thin films, n-
type thin films, and an intrinsic substrate relating the two.
The p/n junction is in all those components, including the
base material itself, and cannot be seen.
     Third, we are not persuaded by Sunpreme’s attempt to
distinguish the Triex scope ruling based on perceived dif-
ferences in the cells. Both Sunpreme’s solar modules and
the Triex cells have p/i/n junctions formed by thin films laid
atop a crystalline silicon substrate, wherein the crystalline
silicon substrate facilitates the creation of an electric field
between the thin film layers. Any other differences be-
tween the cells, including the location of the junction or the
method of formation, do not bear on our analysis for the
reasons stated above.
    Finally, Sunpreme’s effort to analogize the facts of this
case to the facts in Duferco is fruitless. In Duferco, Com-
merce interpreted a floor plate product with patterns in
nonrectangular cross-sections achieved from a rolling pro-
cess to be within the scope of an order covering flat-rolled
products of nonrectangular cross-section where the cross-
section was achieved only after rather than during the roll-
ing process. 296 F.3d at 1095. We held that Commerce’s
SUNPREME INC. v. UNITED STATES                            21



interpretation was unlawful because it was completely un-
tethered from the language of the order. Id. at 1095, 1098.
We reasoned that merchandise may only be included
within an order’s scope if that order contains language spe-
cifically targeting the subject merchandise or capable of be-
ing reasonably interpreted to include such merchandise.
Id. at 1089. The same facts do not exist here. Unlike the
duty order in Duferco, which did not include any language
that could act as a hook for the subject merchandise, the
Orders expressly contemplate products having a p/n junc-
tion formed by any means, which for the reasons stated
above can be reasonably interpreted to include p/i/n junc-
tions.
    We therefore agree with the CIT that substantial evi-
dence supports Commerce’s conclusion that Sunpreme’s so-
lar modules contain a p/n junction.
                             D
    Sunpreme argues that Commerce’s ruling that Sun-
preme’s solar modules do not qualify for the thin film ex-
clusion in the Orders is not supported by substantial
evidence. It argues that Commerce rewrote the scope of
the exclusion by interpreting it as not covering solar prod-
ucts containing active crystalline silicon wafers because
the language of the exclusion and (k)(1) sources do not sug-
gest discriminating among products based on the thin film
substrate. It contends that its solar modules are thin films
based on their industry certification, their size, and the
way in which they are produced. Finally, Sunpreme as-
serts that SolarWorld’s statements during the ITC confer-
ence demonstrate the scope of the exclusion is broader than
Commerce’s interpretation because there is no overlap be-
tween thin films and crystalline silicon cells, and the only
competitive injury contemplated by the industry was with
respect to crystalline silicon products rather than thin
films.
22                           SUNPREME INC. v. UNITED STATES




    The United States and SolarWorld respond that Com-
merce correctly interpreted the thin film exclusion as not
extending to Sunpreme’s solar modules. They argue that
the language of the exclusion in the Orders is capable of
bearing a narrow interpretation and (k)(1) sources support
that understanding. Additionally, they encourage us to
discount the value of the industry certifications Sunpreme
identifies with respect to its solar modules because those
modules are certified as both crystalline silicon and thin
film products. Finally, SolarWorld argues that Sunpreme
misconstrues its representative’s statements at the ITC
conference.
      Substantial evidence supports Commerce’s conclusion
that Sunpreme’s solar modules do not qualify for the thin
film exclusion. It was a reasonable interpretation of the
Orders, based on their plain language and (k)(1) sources,
for Commerce to determine that the thin film exclusion
does not protect those products that have both thin films
and an active crystalline silicon wafer. The Orders provide
that the covered merchandise “is crystalline silicon photo-
voltaic cells” and the excluded merchandise includes “thin
film photovoltaic products produced from amorphous sili-
con (a-Si), cadmium telluride (CdTe), or copper indium gal-
lium selenide (CIGS).” CVD Order, 77 Fed. Reg. at 73,017;
AD Order, 77 Fed. Reg. at 73,018. The petition clearly
states that thin film products “do not use crystalline silicon
. . . .” J.A. 551. And the ITC asserted in its investigation
that “CSPV products and thin film products have different
chemical compositions and physical characteristics that af-
fect the inherent properties of each and may limit their in-
terchangeability,” making particular note that traditional
CSPV cells are made from crystalline silicon and are more
efficient while thin films are typically made of amorphous
silicon or non-silicon materials. J.A. 309, 326–27. The ITC
also determined in its investigation that thin film products
tend to use glass substrates or a flexible substrate such as
SUNPREME INC. v. UNITED STATES                            23



stainless steel or plastic. Those sources strongly suggest
that thin films do not incorporate crystalline silicon.
     Moreover, in the Triex scope ruling, Commerce distin-
guished CSPV cells from thin film products for purposes of
the Orders. Relying on the petition and the ITC’s initial
investigation, Commerce said conventional thin films were
designed to avoid the use of crystalline silicon and instead
use a-Si, CdTe, or CIGS on a non-functional substrate like
glass. It determined that the Triex cells do not qualify for
the thin film exclusion because they “contain a crystalline
silicon component that contributes to their photovoltaic
function.” J.A. 871.
    Because there is no dispute that Sunpreme’s solar mod-
ules contain crystalline silicon, and the evidence demon-
strates that the crystalline silicon plays an active role in
the cells energy generation processes as stated above, Sun-
preme’s solar modules do not qualify for the thin film ex-
clusion. We agree with the CIT’s decision to uphold
Commerce’s interpretation of the Orders because allowing
any product that contains any thin film layer to qualify for
the thin film exclusion “would result in a physical descrip-
tion that would easily permit circumvention of the scope of
the Orders.” J.A. 872.
     Sunpreme’s arguments trying to chip away at Com-
merce’s reasonable conclusion are unpersuasive. First,
Commerce’s interpretation does not rewrite the scope of the
thin film exclusion by defining it based on the substrate
used, but instead its interpretation reasonably construes
the exclusion to prevent it from covering products that are
drawn to the central focus of the Orders: active crystalline
silicon. Second, although SolarWorld’s representative
stated at the ITC conference that it was not concerned with
certain hybrid solar cell products that used both crystalline
silicon wafers and amorphous silicon thin film layers, he
noted that his lack of concern was merely because those
hybrid products were limited in availability and
24                          SUNPREME INC. v. UNITED STATES




production. Earlier in the conference, SolarWorld stressed
that thin film technologies are “completely separate” from
crystalline silicon products and the two do not overlap in
their application. J.A. 370. Last, even if Sunpreme’s solar
modules are certified by the International Electrotechnical
Commission as thin film products, we are not persuaded
that the scope of the Orders is dictated by or otherwise
tethered to such industry certifications. We therefore con-
clude that substantial evidence supports Commerce’s de-
termination that Sunpreme’s solar modules are not
excluded thin films.
    In sum, we agree with the CIT that substantial evi-
dence supports Commerce’s final scope ruling. Sunpreme’s
solar modules are covered by the Orders.
                             II
     We now turn to the cross-appeal filed by the United
States and SolarWorld which is the subject of the petition
for rehearing en banc, asking us to reinstate the portion of
Commerce’s instructions to Customs held invalid by the
CIT.
    Commerce issued the Orders in December 2012. De-
spite the Orders, Sunpreme identified its imported mod-
ules as type 01 entries, meaning that the entries were not
subject to antidumping and countervailing duties. In April
2015, however, Customs began to question Sunpreme’s
identification of its products as type 01 entries. Customs
determined that the products were in fact covered by the
Orders and, beginning on April 20, 2015, directed Sun-
preme to instead enter its products as type 03 entries,
which require payment of antidumping and countervailing
duty cash deposits. In the hopes of avoiding this treatment,
Sunpreme requested a scope inquiry to determine whether
its products were in fact within the scope of the Orders.
Commerce initiated a formal scope inquiry on December
30, 2015. At the conclusion of the scope inquiry, Commerce
determined that Sunpreme’s modules did in fact fall within
SUNPREME INC. v. UNITED STATES                            25



the scope of the Orders. Accordingly, Commerce instructed
Customs to continue the suspension of liquidation and col-
lection of cash deposits for Sunpreme modules, which had
begun in April 2015. Sunpreme challenged those instruc-
tions at the CIT.
    The CIT vacated Commerce’s instructions in-part,
holding that the suspension of liquidation could not law-
fully cover modules entered prior to the initiation of a for-
mal scope inquiry on December 30, 2015. A panel majority
of this court agreed. Panel Opinion, 924 F.3d at 1215–16.
The United States now asks us en banc to reverse that con-
clusion, and to reimpose the portion of Commerce’s instruc-
tions suspending liquidation for entries between April 20,
2015 and December 30, 2015.
                             A
     Under the clear and unambiguous terms of the rele-
vant regulation, when Commerce conducts a scope inquiry
“and the product in question is already subject to suspen-
sion of liquidation, that suspension of liquidation will be
continued” pending the final scope ruling. 19 C.F.R.
§ 351.225(l)(1) (emphasis added). When Commerce issues
a final scope ruling “to the effect that the product in ques-
tion is included within the scope of the order, any suspen-
sion of liquidation under paragraph (l)(1) or (l)(2) will
continue.” 19 C.F.R. § 351.225(l)(3) (emphasis added). If
there has been no previous suspension of liquidation, and
the final scope ruling is that the product is covered by the
order, then Commerce is instead commanded by subsection
(l)(3) to instruct Customs to suspend liquidation and collect
the requisite cash deposit “for each unliquidated entry of
the product entered, or withdrawn from warehouse, for
consumption on or after the date of initiation of the scope
inquiry.” Id. (emphasis added). Alternatively, if the final
scope ruling is that the product in question was not within
the scope of the order, subsection (l)(3) provides that Com-
merce will order any previous suspension of liquidation
26                           SUNPREME INC. v. UNITED STATES




ended and instruct Customs to refund cash deposits al-
ready made or release any bonds relating to the product.
     Customs began suspending liquidation of Sunpreme’s
subject solar modules on April 20, 2015, prior to the initia-
tion of the scope inquiry. Under a straightforward applica-
tion of subsection (l)(1), that suspension of liquidation
“continued” through the duration of the scope inquiry.
When Commerce issued its final scope ruling confirming
that the modules were within the scope of the Orders, sub-
section (l)(3) required that the existing “suspension of liq-
uidation under paragraph (l)(1) . . . will continue.”
Consistent with that regulation, Commerce instructed that
Customs should continue its suspension of liquidation for
entries dating back to April 20, 2015. As a result, Sun-
preme was required to pay antidumping duties for products
falling within the Orders beginning with the initial suspen-
sion of liquidation on April 20, 2015.
     The CIT, however, did not reach this result. Instead,
it held that the suspensions of liquidation beginning in
April of 2015 were ultra vires acts by Customs because they
required Customs to interpret ambiguous orders, and
therefore were of no legal effect. Sunpreme II CIT, 256
F. Supp. 3d at 1292. Citing our decisions in AMS Associ-
ates., Inc. v. United States, 737 F.3d 1338 (Fed. Cir. 2013)
and Xerox Corp. v. United States, 289 F.3d 792 (Fed. Cir.
2002), the CIT concluded that Customs “lacks the authority
to interpret ambiguous scope language.” Sunpreme II CIT,
256 F. Supp. 3d at 1292. Therefore, the CIT held, no valid
suspensions of liquidation existed that could be “continued”
during the scope inquiry under subsection (l)(1). With no
legally effective ongoing suspensions of liquidation, Com-
merce would have instead faced the situation under sub-
section (l)(3) “where there has been no suspension of
liquidation.” In that instance, Commerce’s instructions to
Customs would be limited to products “entered on or after
the date of initiation of the scope inquiry,” here December
30, 2015. Based on its interpretation of our caselaw, the
SUNPREME INC. v. UNITED STATES                           27



CIT vacated the portion of Commerce’s instructions that
would have continued the suspension of liquidation for
modules entered prior to that date.
    The question before us, then, is whether Customs acted
within its authority when it initially interpreted the Or-
ders to cover Sunpreme’s solar modules and began suspen-
sion of liquidation. If it did, Sunpreme is required to pay
antidumping and countervailing duties on products im-
ported on or after April 20, 2015 (when Customs first de-
termined that Sunpreme’s modules were within the scope
of the Orders and began collecting cash deposits). How-
ever, if Customs exceeded its authority when it interpreted
the Orders, then Sunpreme is only required to pay duties
on products imported on or after December 30, 2015 (the
date the scope inquiry was initiated). Sunpreme would
thus be refunded its cash deposits for modules imported be-
tween April 20 and December 30, despite our conclusion in
Part I that Sunpreme’s modules are within the scope of the
Orders.
     For the reasons explained below, we break from the
CIT and the prior panel opinion in this case, and now hold
that Customs did not exceed its authority by ordering the
suspension of liquidation based on its interpretation of the
Orders. Customs has a statutory responsibility to fix the
amount of duty owed on imported goods. See 19 U.S.C.
§ 1500(c). As part of that responsibility, Customs is both
empowered and obligated to determine in the first instance
whether goods are subject to existing antidumping or coun-
tervailing duty orders. While Customs may not expand or
alter the scope of such orders, its authority and responsi-
bility to determine whether they apply does not dissipate
simply because an order lacks perfect clarity. Contrary to
the CIT’s conclusion, Customs’s yes-or-no answer to
whether an order applies does not invade the interpretive
province of Commerce. Any other result would signifi-
cantly limit Customs’s ability to perform its statutory role
28                            SUNPREME INC. v. UNITED STATES




and would encourage gamesmanship by importers hoping
to receive the type of windfall that Sunpreme seeks here.
                               B
     The Tariff Act of 1930 requires Commerce to impose
two types of duties on imports of goods that may injure do-
mestic industries. When “foreign merchandise is being, or
is likely to be, sold in the United States at less than its fair
value,” Commerce imposes an antidumping duty.
19 U.S.C. § 1673. Similarly, when a foreign government
subsidizes the manufacture or export of goods imported or
sold into the United States, Commerce imposes a counter-
vailing duty. See 19 U.S.C. § 1671.
    When goods are imported into the United States, Cus-
toms is obligated to “fix the final amount of duty to be paid
on such merchandise and determine any increased or addi-
tional duties, taxes, and fees due.” 19 U.S.C. § 1500(c).
That obligation necessarily requires Customs to make a de-
termination as to whether existing antidumping or coun-
tervailing duty orders apply to the subject goods. See
Mukand Int’l, Ltd. v. U.S., 502 F.3d 1366, 1367 (Fed. Cir.
2007) (noting that after Commerce has issued an anti-
dumping duty order “Customs is thereafter responsible for
applying and enforcing the order”); Xerox, 289 F.3d at 794
(“When merchandise may be subject to an antidumping
duty order, Customs makes factual findings to ascertain
what the merchandise is, and whether it is described in an
order.”). Neither section 1500 nor any related provision
limits that obligation to the circumstance in which the or-
der is clear and unambiguous. To the contrary, such a lim-
itation would prevent Customs from performing its
statutory obligations to “fix the final amount of duty” and
“collect any increased or additional duties and fees due.”
19 U.S.C. §§ 1500(c), 1505(b). Indeed, Customs is legally
prohibited from releasing goods that are subject to an anti-
dumping or countervailing duty order, ambiguous or not,
unless the importer pays a cash deposit. See 19 U.S.C.
SUNPREME INC. v. UNITED STATES                              29



§ 1671h (“[F]or all entries . . . of merchandise subject to a
countervailing duty . . . no customs officer may deliver mer-
chandise of that class or kind to the person by whom or for
whose account it was imported unless that person . . . de-
posits with the appropriate customs officer an estimated
countervailing duty”); § 1673g(a) (providing the same for
antidumping duties). Nothing in this statutory scheme
suggests that Customs may simply ignore ambiguous or-
ders when it “fix[es] the final amount of duty” owed on
goods. 19 U.S.C. § 1500(c).
     Our conclusion is further bolstered by section 1514(b),
which provides that “determinations of the Customs Ser-
vice,” including whether goods fall within the scope of an
antidumping or countervailing duty order, “are final and
conclusive” unless appealed to Commerce. 19 U.S.C.
§ 1514(b); see also Fujitsu Ten Corp. v. United States, 957
F. Supp. 245, 248 (Ct. Int’l Trade 1997) (Wallach, J.) (“The
statute recognizes Customs makes the initial determina-
tion that an existing antidumping order applies to a spe-
cific entry of merchandise. The statute states that such a
decision is ‘final and conclusive’ unless it is appealed by pe-
tition to Commerce.” (citations omitted)). We see little
room for an interpretation in which Customs is tasked by
section 1500 to “fix the final amount of duty,” and by sec-
tion 1514 to do so “final[ly] and conclusive[ly],” but is im-
plicitly prohibited from doing so in cases that are less than
perfectly clear.
    Any other result would also be inconsistent with
19 C.F.R. § 351.225(l). That regulation expressly contem-
plates a scenario in which products are “subject to suspen-
sion of liquidation” at the direction of Customs, but
Commerce later initiates a scope inquiry and issues a “final
scope ruling [] to the effect that the product in question is
not included within the scope of the order” (i.e., that Cus-
toms’s initial determination was incorrect). See id. Such a
regulation would be largely unnecessary if Customs was
30                             SUNPREME INC. v. UNITED STATES




only empowered to suspend liquidation where orders were
clear and unambiguous.
                                C
    We recognize that the CIT’s conclusion and Sunpreme’s
arguments are rooted not in the language of any statute or
regulation, but in our caselaw. As discussed below, how-
ever, we do not agree that either of the cases relied upon
prohibit Customs from suspending liquidation based on an
ambiguous order.
    The CIT, relying on AMS Associates., Inc. v. United
States, 737 F.3d 1338 (Fed. Cir. 2013), stated that:
     where an unclear order renders a product not subject
     to an existing order and Commerce clarifies ambig-
     uous scope language to determine that the merchan-
     dise is subject to the antidumping order, “the
     suspension of liquidation and imposition of anti-
     dumping cash deposits may not be retroactive but
     can only take effect on or after the date of the initia-
     tion of the scope inquiry.”
Sunpreme II CIT, 256 F. Supp. 3d at 1292 (quoting AMS,
737 F.3d at 1344) (emphasis original to AMS). Applying
that holding to this case, however, contorts the meaning of
the terms “not subject to an existing order” and “retroac-
tive” in a manner that runs contrary to AMS itself.
    In AMS, Customs made an initial determination that
the goods in question were “not subject to the antidumping
duty order.” Id. at 1340. As a result, “those entries were
consequently not subject to antidumping deposits.” Id. In
a later administrative review, Commerce “clarified” the
scope of the order, to the effect that the goods fell within its
scope. As a result, Commerce issued instructions to sus-
pend liquidation, retroactively and for the first time, of
goods entered prior to the review and never previously sus-
pended. Id. at 1343, 1344.
SUNPREME INC. v. UNITED STATES                            31



    AMS is factually distinct from the present case in two
meaningful ways. First, in AMS, Customs originally deter-
mined that the goods were not within the scope of the am-
biguous order. Here, Customs found (correctly) that the
goods were within the scope of the order. The CIT correctly
noted that AMS’s holding is limited to cases “where an un-
clear order renders a product not subject to an existing or-
der.” Sunpreme II CIT, 256 F. Supp. 3d at 1292. But it
would be error to include this case—in which the products
were found to be subject to an existing order, even if that
order was unclear—in that same category.
     Second and more importantly, as a result of the origi-
nal determination, Customs had not suspended liquidation
in AMS. Despite that, Commerce ordered the suspension
of liquidation, retroactive to even before the initiation of
the scope inquiry. As we noted in AMS, that was a clear
violation of 19 C.F.R. § 351.225(l)(2). Commerce may not
suspend liquidation in a manner that causes merchandise
that previously entered not subject to duties to be retroac-
tively brought within the scope of duty orders. But that
rule has no bearing on this case, where the goods in ques-
tion entered subject to duties, have always been subject to
duties, and will now continue to be subject to duties. There
is nothing “retroactive” about continuing to suspend liqui-
dation where liquidation has already been suspended for
the entire relevant time period.
    Indeed, subsection (l)(3) distinguishes exactly these
two scenarios. When Commerce rules that a product falls
within the scope of an order, but “there has been no [previ-
ous] suspension of liquidation,” a new suspension must be
ordered beginning only “on or after the date of initiation of
the scope inquiry.” 19 C.F.R. § 351.225(l)(3). Anything else
would be impermissibly retroactive, as we acknowledged in
AMS. But where, as here, a suspension that predates the
scope inquiry already exists, subsection (l)(3) instead dic-
tates that the existing suspension “will continue.” Id. No
32                           SUNPREME INC. v. UNITED STATES




retroactivity concerns are raised because no new suspen-
sion occurs.
    Any other outcome would run counter to the principles
set forth in AMS itself. The AMS court rejected an inter-
pretation of the scope inquiry regulations that “would per-
mit importers to potentially avoid paying antidumping
duties on past imports by asserting unmeritorious claims
that their products fall outside the scope of the original or-
der.” 737 F.3d at 1344. Yet the CIT’s analysis here leads
to a similar result. Under the CIT’s view of AMS, Sun-
preme would be entitled to a refund of cash deposits and
duties paid on goods entered between April and December
2015, as a result of its unmeritorious challenge to Com-
merce, even though Customs, Commerce, the CIT, and this
court have all now concluded that Sunpreme’s modules fall
within the scope of the Orders.
    The CIT separately relied on Xerox Corp. v. United
States, 289 F.3d 792 (Fed. Cir. 2002) to conclude that Sun-
preme’s “goods were outside the scope of the Orders until
Commerce interpreted the ambiguous scope language . . .
because [Customs] lacks the authority to interpret ambig-
uous scope language.” Sunpreme II CIT, 256 F. Supp. 3d
at 1292. We do not agree.
    Xerox did not address Customs’s authority to take or
not take any interpretive action. Rather, it presented a
question of the Court of International Trade’s jurisdiction:
whether, under the facts of that case, the proper method of
appeal was to protest to Customs, or to request a scope de-
termination by Commerce. 289 F.3d at 793. Notably,
Xerox did not concern an ambiguous order at all. As this
court made clear in that case, “the scope of the order is not
in question . . . the belts at issue are facially outside the
scope of the antidumping duty order.” Id. at 795.
     It is true that, in summarizing the scope inquiry pro-
cess, this court in Xerox described Customs’s authority to
“fix[] the amount of duty to be paid” as “ministerial.” Id. at
SUNPREME INC. v. UNITED STATES                          33



794 (citing 19 U.S.C. § 1500(c)). We used the same term in
Mitsubishi Electronics. America, Inc. v. United States, 44
F.3d 973, 977 (Fed. Cir. 1994), in distinguishing Customs’s
ministerial authority from Commerce’s broader authority,
noting that Customs may not “modify Commerce’s deter-
minations, their underlying facts, or their enforcement.”
Id. (quoting Royal Bus. Machs., Inc. v. United States, 507
F. Supp. 1007, 1014 n.18 (Ct. Int’l Trade 1980) (internal
quotations and modifications omitted)). But we did not
hold or state in Xerox or Mitsubishi that the “ministerial”
duty of Customs excludes “interpret[ing] ambiguous scope
language,” Sunpreme II CIT at 1292, for the limited but
essential purpose of making the daily, yes-or-no decisions
about whether a particular product meets the test of an an-
tidumping or countervailing duty order. The term “minis-
terial” often is used to contrast the presence of certain
kinds of discretion or judgment. See, e.g., Dep’t of Home-
land Sec. v. MacLean, 135 S. Ct. 913, 922 (2015); Kendall
v. Stokes, 44 U.S. (3 How.) 87, 98 (1845); Black’s Law Dic-
tionary 1192 (11th ed. 2019). We need only say that we did
not use the term in Xerox or Mitsubishi so narrowly as to
exclude the individual product-by-product application deci-
sions Customs is required by law to make, which do not
invoke the kind of deference-deserving, boundary-defining
authority reserved to Commerce when it interprets or clar-
ifies an order during scope proceedings.
    Customs is tasked with determining, for every im-
ported product, whether the product falls within the scope
of an antidumping or countervailing duty order. 19 U.S.C.
§ 1500(c). That necessarily entails evaluating both the
product and the order. Xerox recognizes as much. 289 F.3d
at 794 (“When merchandise may be subject to an anti-
dumping duty order, Customs makes factual findings to as-
certain what the merchandise is, and whether it is
described in an order. If applicable, Customs then assesses
the appropriate antidumping duty.” (internal citation omit-
ted)). In each instance, Customs is statutorily tasked with
34                           SUNPREME INC. v. UNITED STATES




answering a yes-or-no question as to whether the order ap-
plies, in order to fix the duty owed. When the order is am-
biguous, Customs is nonetheless called upon to answer the
question. As we have described, “[w]hen Customs believes
an antidumping duty order covers a particular imported
good, it suspends liquidation of that entry.” Mukand,
502 F.3d at 1367 (emphasis added). Answering that ques-
tion does not transform Customs’s yes-or-no question into
an interpretive act that would “modify Commerce’s deter-
minations” or otherwise impinge upon Commerce’s author-
ity to issue and set the scope of duty orders.
     Finally, we address the CIT and Sunpreme’s citations
to Xerox, which in turn cites Sandvik Steel Co. v. United
States, 164 F.3d 596 (Fed. Cir. 1998), for the proposition
that “Commerce should in the first instance decide whether
an antidumping order covers particular products.” Sun-
preme II CIT at 1293 (citing Xerox, 289 F.3d at 794–95);
Appellant’s Response to Petition for Rehearing, at 11. That
out-of-context citation is inapplicable here. The question
presented in Sandvik was whether an importer has
properly exhausted its administrative remedies when it de-
clines to file a scope inquiry with Commerce, but instead
files a protest with Customs and in turn appeals to the CIT.
This court held that such an approach was impermissible,
in part because it effectively circumvented any ruling from
Commerce, which “should in the first instance” rule on the
scope of an antidumping duty order. Sandvik, 164 F.3d at
602. In other words, Sandvik stands for the proposition
that Commerce should evaluate the scope of an order before
the issue reaches the CIT. It does not hold that any inter-
pretation by Customs prior to Commerce conducting a
scope inquiry is invalid. Indeed, as Xerox notes, liquidation
was suspended in Sandvik despite the fact that “it was un-
clear whether the goods at issue were within the scope of
antidumping duty orders.”          289 F.3d at 795 (citing
Sandvik, 164 F.3d at 598–99). Sandvik did not disapprove
of suspensions based on unclear orders.
SUNPREME INC. v. UNITED STATES                             35



    For the reasons discussed above, neither AMS nor
Xerox controls the outcome of this case. Under a proper
reading, neither is contrary to our current holding that
Customs has the authority to suspend liquidation of goods
when it determines that the goods fall within the scope of
an ambiguous antidumping or countervailing duty order.
In the interest of clarity, however, to the extent any por-
tions of AMS or Xerox could be read as contrary to this hold-
ing, those portions are hereby overruled.
                              D
     In addition to being consistent with the relevant stat-
utes, regulations, and caselaw, our holding that Customs
may suspend liquidation of goods based on ambiguous duty
orders elides significant policy concerns that would be cre-
ated by the alternative outcome. Our decision in this case
is driven by the law, and not by policy considerations. But,
when a policy is declared in a statute, we must consider
and “follow the policy Congress has prescribed.” SAS Inst.,
Inc. v. Iancu, 138 S. Ct. 1348, 1358 (2018). Sunpreme’s lim-
ited view of Customs’s authority runs afoul of the policy
declared in the Tariff Act, which instructs the government
to “provide, to the maximum extent practicable, for the pro-
tection of revenue.” 19 U.S.C. § 1484(a)(2)(C); see also
Guangdong Wireking Housewares & Hardware Co., Ltd v.
U.S., 745 F.3d 1194, 1203 (Fed. Cir. 2014) (“The congres-
sional intent behind the enactment of countervailing duty
and antidumping law generally was to create a civil regu-
latory scheme that remedies the harm unfair trade prac-
tices cause.”); see also id. (noting that the statutory scheme
has a “curative purpose” and a “remedial intent”).
    Barring Customs from suspending liquidation based on
ambiguous orders would create perverse incentives for im-
porters, contrary to the remedial and revenue-driven policy
of the statute. The Orders went into effect in December
2012, and imposed antidumping and countervailing duties
on CSPV cells “having a p/n junction formed by any means,
36                           SUNPREME INC. v. UNITED STATES




whether or not the cell has undergone other processing.”
CVD Order, 77 Fed. Reg. at 73,017; AD Order, 77 Fed. Reg.
at 73,018–19. Contrary to the Orders, Sunpreme entered
its modules without depositing duties until April 2015,
when Customs determined that the modules fell within the
scope of the Orders and ordered the suspension of liquida-
tion. Since then, Commerce, the CIT, a unanimous panel
of this court, and now an en banc majority of this court have
all also concluded that Sunpreme’s modules contain “a p/n
junction formed by any means.” Yet, if Customs could not
have lawfully suspended liquidation, Sunpreme would now
receive a refund for duties it paid between April 2015 and
December 2015.
                        CONCLUSION
     For the reasons stated above, we affirm the CIT’s con-
clusion that Commerce’s final scope ruling placing Sun-
preme’s solar products within the ambit of the Orders is
supported by substantial evidence. We reverse, however,
the CIT’s determination that Commerce’s instructions to
Customs are invalid to the extent that they require contin-
uation of suspension of liquidation and collection of cash
deposits on Sunpreme’s solar modules entered or with-
drawn from warehouse for consumption before Commerce
initiated its scope inquiry on December 30, 2015. Com-
merce’s liquidation instructions are reinstated in full.
     AFFIRMED-IN-PART and REVERSED-IN-PART
                           COSTS
      Costs to the United States and SolarWorld.
