                            In the

United States Court of Appeals
              For the Seventh Circuit

Nos. 07-3863 & 07-3864

IN RE:

    A IRADIGM C OMMUNICATIONS, INC.,
                                                              Debtor.

A IRADIGM C OMMUNICATIONS, INC. and
T ELEPHONE AND D ATA S YSTEMS, INC.,
                                                           Appellants,
                                v.


F EDERAL C OMMUNICATIONS C OMMISSION,
                                                             Appellee.


           Appeals from the United States District Court
              for the Western District of Wisconsin.
             No. 07 C 307 S—John C. Shabaz, Judge.


   A RGUED S EPTEMBER 16, 2008—D ECIDED O CTOBER 29, 2008




  Before C UDAHY, F LAUM, and R OVNER, Circuit Judges.
  F LAUM, Circuit Judge. Debtor-appellant Airadigm Com-
munications, Inc. purchased fifteen personal communica-
tions services (“PCS”) licenses in 1996 through FCC
auctions. It planned to pay for these licenses in install-
2                                   Nos. 07-3863 & 07-3864

ments. Unable to meet its payment obligations, Airadigm
filed for Chapter 11 bankruptcy in 1999. Its plan of reorga-
nization, confirmed on November 15, 2000, was dependent
upon financing by Telephone and Data Systems (“TDS”).
The reorganization plan provided the FCC an allowed
claim of $64.2 million for the fifteen licenses. The FCC took
the position that the licenses were forfeited as a result
of Airadigm’s failure to pay in full, and Airadigm’s
Chapter 11 case proceeded as if the licenses were no
longer an asset of the company. In 2003, however, the
Supreme Court decided FCC v. NextWave Personal Com-
munications, Inc., 537 U.S. 293 (2003). That case held that
the FCC could not cancel a license because the licensee
had filed for bankruptcy prior to paying for the license.
The FCC then conceded that it had incorrectly
terminated Airadigm’s licenses, and it reinstated them.
  Airadigm filed a second Chapter 11 petition in May 2006.
TDS again would provide financing. On September 14,
2006, the FCC filed a claim for each of the licenses, seeking
the principal amounts owed on the licenses (about
$64.2 million) and accrued interest on the claims through
the 2006 petition date (about $42.4 million). Airadigm and
TDS objected to the FCC’s claims for interest, arguing
that under the 2000 plan all interest stopped accruing
on the 1999 petition date.
  The bankruptcy court denied the FCC interest for the
period from the commencement of the bankruptcy case
to the November 15, 2000 confirmation date, but it
found that the 2000 plan implicitly entitled the FCC to
post-confirmation interest. The district court affirmed the
Nos. 07-3863 & 07-3864                                      3

bankruptcy court in part to allow post-confirmation
interest and reversed the bankruptcy court in part to
also allow a portion of the additional interest that the
FCC sought. Airadigm and TDS appeal. For the reasons
explained below, we affirm the district court’s ruling
awarding post-confirmation interest for the period
between confirmation of Airadigm’s 2000 plan of reorgani-
zation and commencement of new bankruptcy pro-
ceedings in 2006; and we affirm the district court’s
award of post-petition interest for the interim period
between commencement of the 1999 bankruptcy pro-
ceeding and confirmation of the 2000 plan.


                      I. Background
   The FCC awards spectrum licenses—which can be used
for a variety of mobile and fixed radio services—for
specific time periods. The Communications Act of 1934,
as amended, authorizes the FCC to allocate spectrum
licenses through a system of competitive bidding, based
on the premise that the highest qualified bidder will be
most likely to build out the licenses and put them to
public use. 47 U.S.C. § 309(j)(1). This Act further requires
the FCC to design auctions that “ensure that small busi-
nesses, rural telephone companies, and businesses
owned by members of minority groups and women are
given the opportunity to participate in the provision of
spectrum-based services.” 47 U.S.C. § 309(j)(3)(B), (j)(4)(D).
The FCC earmarked certain blocks of spectrum—blocks C
and F—for such entities who, unable to afford a lump
sum payment, could pay for their licenses in installments.
4                                   Nos. 07-3863 & 07-3864

47 C.F.R. § 24.709 (2007). To ensure payment, the FCC
made payment-in-full a condition precedent to obtaining
a license, 47 C.F.R. § 1.2110(g)(4)(iv), and it executed a
promissory note and security agreement to secure its
interest in each license. Id. § 1.2110(g)(3). If the success-
ful bidder fell into default, “its license [would] automati-
cally cancel, and it [would] be subject to debt collection
procedures.” 47 C.F.R. § 1.2110(g)(4)(iv).
   In a 1996 FCC auction, Airadigm was the highest
bidder for fifteen licenses designated for small busi-
nesses. Thirteen of these licenses were “C-block” and two
were “F-block” segments. The licenses authorized
Airadigm to use portions of the electromagnetic
spectrum to provide wireless telecommunications
services in parts of Wisconsin, Iowa, and Michigan.
Airadigm agreed to pay for these licenses in quarterly
installments, plus interest, over a ten-year period.
Airadigm paid ten percent of the purchase price, signed
fifteen promissory notes recognizing its debt to the FCC,
and executed fifteen security agreements. The licenses
themselves stated that they were conditioned on the “full
and timely payment of all monies due pursuant to
[FCC regulations] and the terms of the Commission’s
installment plan.” The licenses stated that failure to
comply with this condition would result in automatic
cancellation of the licenses. The FCC sought to perfect
its interest in the licenses by, among other things, filing
UCC financing statements with the office of the Wis-
consin Secretary of State.
  Airadigm soon met financial problems. It defaulted on its
obligations to the FCC and filed a voluntary petition
Nos. 07-3863 & 07-3864                                     5

for Chapter 11 relief on July 28, 1999. The FCC allowed
Airadigm to continue using its portion of the spectrum
but cancelled Airadigm’s licenses and filed a proof of
claim in bankruptcy court for about $64.2 million, which
represented the aggregate unpaid principal balance
due under the fifteen notes. The FCC stated that the
licenses had automatically cancelled by operation of law
and that, as its collateral had been extinguished, its claims
against Airadigm were unsecured. Hedging, the FCC
recognized in its proof of claim that if it did not have
the authority to cancel the licenses, its debt was instead
secured by the licenses themselves. Airadigm filed a
petition with the FCC seeking either reinstatement of
the licenses or a waiver of their cancellation.
  In October 2000, Airadigm and several other interested
parties filed a plan of reorganization. The FCC objected
to confirmation of the plan, but it limited its objection to
the plan’s treatment of the FCC as the holder of an unse-
cured claim. On November 1, 2000, a confirmation
hearing was held on the debtor’s plan. On November 15,
2000, the bankruptcy court entered an order confirming
the 2000 plan. The FCC did not appeal.
  The reorganization proceeded under the assumption
that the FCC had properly cancelled the licenses. The
plan provided that the FCC had an allowed claim of
$64.2 million and laid out several contingencies should
the FCC reinstate the licenses. TDS would provide the
financing under these contingency scenarios. Should the
FCC reinstate the licenses by June 2001, TDS would pay
the FCC’s claim in full. If the FCC did not reinstate the
6                                    Nos. 07-3863 & 07-3864

licenses by June 2001 but did so by June 2002, TDS had
the option of paying off the claim but was not obligated
to do so. But if the FCC never reinstated the licenses or
“fail[ed] to act . . . in a timely manner,” the plan provided
that TDS would obtain all of Airadigm’s assets except
the licenses. The plan was otherwise silent as to the
FCC’s exact interests in the licenses and what would
happen if the FCC reinstated them after June 2002. And
the plan did not expressly preserve the FCC’s security
interest in the licenses, instead stating that the plan “shall
not enjoin or in any way purport to limit, restrict, affect
or interfere with action initiated by the FCC in the full
exercise of its regulatory rights, powers and duties
with respect to the Licenses.”
   The FCC did not act on the reinstatement petition by
June 2002. On January 27, 2003, the Supreme Court issued
its decision in F.C.C. v. NextWave Personal Communications,
Inc., 537 U.S. 293 (2003). In a case involving a factual
scenario very similar to this one, the Court held that
the FCC could not cancel a debtor’s PCS licenses just
because it had filed for bankruptcy. The Court held that
automatic cancellation violated § 525 of the Bankruptcy
Code, which provides that a government unit may not
“deny, revoke, suspend, or refuse to renew a license,
permit, charter, franchise, or other similar grant” to a
debtor in bankruptcy “solely because such debtor . . . has
not paid a debt that is dischargeable in the case under
this [Bankruptcy] title or that was discharged under
the Bankruptcy Act.” 11 U.S.C. § 525(a). The Court rea-
soned that even if timely installment payments further
the FCC’s regulatory purposes, the obligation to make
Nos. 07-3863 & 07-3864                                  7

such payments is still a debt within the meaning of § 525,
and that the failure to make payments on such debt
therefore cannot be the sole basis for cancelling the FCC
licenses. NextWave, 537 U.S. at 302-05. The FCC conceded
a few months later that it had been wrong to terminate
Airadigm’s licenses, and it reinstated them as though
they had never been cancelled.
   After the FCC reinstated Airadigm’s licenses, Oneida
Enterprise Development Authority (OEDA), another
Airadigm creditor, filed an objection to the FCC’s claim.
OEDA argued that the FCC’s delay in reinstating the
licenses prejudiced them and the FCC’s claim should be
disallowed for inequitable conduct, deemed waived, or
subordinated to the claims of other creditors. The FCC
responded that its conduct was appropriate and that
there was no legal basis to disallow or subordinate its
claim. Agreeing with the FCC, the bankruptcy court
signed an order granting the motion to dismiss and
ordering “that the FCC’s claim is allowed in the amount
of $64,219,442.55.” The allowance order did not provide
for any interest on the FCC claim.
  On May 8, 2006, Airadigm filed a second Chapter 11
bankruptcy petition. It asserted that a new bankruptcy
proceeding was necessary because in the period between
cancellation of the licenses and their post-NextWave
restoration, the licenses had decreased in value and
could no longer cover Airadigm’s debts. On June 6, 2006,
the parties entered a stipulation agreeing, among other
things, that “The FCC’s allowed claim in the 1999 bank-
ruptcy case shall be allowed in the 2006 bankruptcy case.”
8                                   Nos. 07-3863 & 07-3864

In exchange for this agreement, the FCC agreed not
to object to the closing of the 1999 case and the opening
of the 2006 case. The stipulation further provided that “all
other rights of the parties hereto (including without
limitation, the right of the FCC and TDS to seek inclusion
and allowance of interest on their allowed claims) . . . are
expressly reserved.”
  The FCC then renewed its claim, asserting that the
claim was secured and demanding unpaid principal in
the amount of $64.2 million; accrued interest on the
claims running through the commencement of the 2006
case in the amount of $42.4 million; and post-2006 petition
interest. Airadigm and its financier TDS objected to the
interest claims. They argued that the only claims that
the FCC could pursue were those arising from the 2000
plan, that the FCC had waived any claim to interest by
not specifically including interest on the 1999 proof of
claim form, and that the interest claims were now barred
because the order allowing the FCC’s claim over the
Oneida objection only allowed the debt principal and
made no provision for interest.
  On February 23, 2007, the bankruptcy court held a
hearing on the FCC’s 2006 claims. At that hearing, the
bankruptcy court denied the FCC pre-1999 petition
interest and denied the FCC interest for the period between
commencement of the 1999 case and confirmation of the
2000 reorganization plan. It reasoned that these claims
were excluded by the order on the Oneida objection
setting the amount of the FCC’s allowed claim at
$64.2 million—an amount that included only principal,
Nos. 07-3863 & 07-3864                                    9

without interest. The bankruptcy court did add interest
in the amount of $24,625,118.40 for the period between
confirmation of the 2000 plan (which occurred on Novem-
ber 15, 2000) and commencement of the second bank-
ruptcy case on May 8, 2006. The bankruptcy court found
that the 2000 plan implicitly entitled the FCC to this post-
confirmation interest at the contract rate. It reasoned
that the FCC was a secured creditor with respect to the
licenses restored to Airadigm after NextWave; that secured
creditors must, under § 1129(b) of the Bankruptcy Code,
receive interest on their secured claim if payments are
deferred; and that the award of post-confirmation
interest on the allowed claim, at the market rate specified
in the contract underlying the FCC’s claims, was implicit
in the court’s earlier confirmation order. The bankruptcy
court also held that the FCC was entitled to interest
running from commencement of the 2006 bankruptcy
proceeding on claims pertaining to two of Airadigm’s
licenses.
  Both parties appealed to the district court. The district
court affirmed the decision on prepetition interest
accruing before commencement of the 1999 case. The court
reasoned that the bankruptcy court order denying the
OEDA objection to the FCC’s claim and setting the
amount of the allowed claim did not provide for
prepetition interest. The district court affirmed the bank-
ruptcy court’s award of implicit interest for the period
from November 15, 2000 to May 8, 2006. The court rea-
soned that the bankruptcy court’s construction of its own
prior order confirming Airadigm’s plan of reorganiza-
tion was entitled to deference and was, in any event, “the
10                                  Nos. 07-3863 & 07-3864

only reasonable interpretation of the plan.” Additionally,
the district court reversed the bankruptcy court to hold
that the FCC was entitled to $6.6 million more in
interest for the time period after commencement of the
1999 case through confirmation of the 2000 plan (from
July 28, 1999 through November 15, 2000). The district
court granted this interest based on § 506(b) of the Bank-
ruptcy Code, which requires interest when a claim is
oversecured. The court found that the value of the
licenses securing the claim at the time of the 1999 petition
was greater than the amount of the allowed claim.
  Airadigm and TDS appeal the district court order to
the extent that it awarded implicit interest for the period
from November 15, 2000 to May 8, 2006 and § 506(b)
interest for the period from July 28, 1999 to November 15,
2000. The FCC no longer challenges the denial of pre-1999
petition interest, and Airadigm and TDS no longer chal-
lenge the award of interest for the period following
commencement of the 2006 bankruptcy case.


                      II. Discussion
  A. Standard of Review
  Legal conclusions are reviewed de novo. Findings of fact
may be reversed only if clearly erroneous. In re Outboard
Marine Corp., 386 F.3d 824, 827 (7th Cir. 2004). A bank-
ruptcy court’s interpretation of a plan it confirmed is
subject to full deference as an interpretation of its own
order and may be overturned only if the record shows
an abuse of discretion in the interpretation. In re Weber,
25 F.3d 413, 416 (7th Cir. 1994).
Nos. 07-3863 & 07-3864                                      11

  B. November 15, 2000 to May 8, 2006
   The FCC objected to confirmation of the 2000 plan. To
confirm a plan of reorganization without the consent of
an impaired class (to “cram down” the plan), two condi-
tions must be met. 11 U.S.C. § 1129(a); Bank of Am. Nat’l
Trust & Sav. Ass’n v. 203 North Lasalle Street P’ship, 526 U.S.
434, 441 (1999). First, each requirement of Bankruptcy
Code § 1129(a), other than § (a)(8), must be met. 203 North
Lasalle, 526 U.S. at 441. Second, to override the objection
of the non-consenting class, the plan must “not discrimi-
nate unfairly, and [must be] fair and equitable, with
respect to each class of claims or interests that is
impaired under, and has not accepted, the plan.”
§ 1129(b)(1). To be “fair and equitable” as to an objecting
secured creditor, it is a statutory “requirement” that the
plan’s provisions satisfy one of the following scenarios:
(i) the creditor retains its liens and receives the present
value of its allowed secured claims; (ii) the collateral
securing the debt is sold with the liens attaching to the
funds from the sale; or (iii) the creditor is given the
“indubitable equivalent” of its claim. 11 U.S.C.
§§ 1129(b)(1), (2)(A).
  To satisfy the first scenario, which is the scenario impli-
cated in this case, an objecting secured creditor must be
given “deferred cash payments totaling at least the
allowed amount of such claim, of a value, as of the effec-
tive date of the plan, of at least the value of such holder’s
interest in the estate’s interest in such property.” 11 U.S.C.
§ 1129(b)(2)(A)(i)(II). When payment is deferred, “a
creditor receives the ‘present value’ of its claim only if the
12                                   Nos. 07-3863 & 07-3864

total amount of the deferred payments includes the
amount of the underlying claim plus an appropriate
amount of interest to compensate the creditor for the
decreased value of the claim caused by the delayed pay-
ments.” Rake v. Wade, 508 U.S. 464, 472 n.8 (1993). Section
1129(b)(2)(A)(i)(II) thus requires interest if the claim is to
be paid over time. United Sav. Ass’n v. Timbers of Inwood
Forest, Assocs., Ltd., 484 U.S. 365, 377 (1988).
  In this case, there was initially great uncertainty as to
whether the FCC should be treated as a secured or unse-
cured creditor. At the time of plan confirmation, the
parties believed that the FCC was an unsecured creditor.
The bankruptcy court confirmed a plan that did not
explicitly provide for interest under § 1129(b)(2)(A), which
allows for interest for secured creditors only. Then the
Supreme Court decided NextWave, which made clear
that the FCC was in fact a secured creditor. The FCC
subsequently reinstated the licenses.
  As a secured creditor, the FCC brought this litigation,
retroactively seeking interest under § 1129(b)(2)(A). The
bankruptcy court awarded this interest to the FCC. The
court noted that, as a result of pending disputes over
whether the licenses should be restored to Airadigm, the
FCC’s status as a secured creditor was not certain at the
time of plan confirmation. It reasoned, however, that
NextWave, and the subsequent reinstatement of licenses,
made clear that the FCC was in fact a secured creditor.
Since the FCC was a secured creditor, the bankruptcy
court found that interest under § 1129(b)(2)(A)(i) was
“implicit” in the 2000 plan, and it awarded this interest
to the FCC. The bankruptcy court explained:
Nos. 07-3863 & 07-3864                                        13

    It was implicit in that confirmation over the objection
    of what we subsequently learned was a secured credi-
    tor that they were entitled to that much. So on their
    allowed secured claim, the payment of which was
    deferred, they’re entitled to receive something to
    bring that deferred payment to present value which
    we call interest.
  There is an issue in this case whether, in allowing interest
under § 1129(b)(2)(A), the bankruptcy court merely
interpreted the reorganization plan that it had devised, or
whether it actually modified the plan. This question is
crucial, as a bankruptcy court interpretation is entitled to
our full deference and can only be overturned for abuse
of discretion, Weber, 25 F.3d at 416; In re Chicago, Milwaukee,
St. Paul & Pacific R.R. Co., 961 F.2d 1260, 1264 (7th Cir.
1992), whereas a plan cannot be modified for any rea-
son after substantial consummation, 11 U.S.C. § 1127(b);
In re CF & I Fabricators of Utah, Inc., 150 F.3d 1233, 1238
(10th Cir. 1998); Goodman v. Phillip R. Curtis Enters., Inc., 809
F.2d 228 (4th Cir. 1987), and there is authority for the
proposition that a sua sponte modification by the bank-
ruptcy court is not permitted at any time. See, e.g., Beal
Bank, S.S.B. v. Jack’s Marine, Inc., 201 B.R. 376, 380 (E.D. Pa.
1996) (“Though a bankruptcy court exercises its equitable
powers at its own discretion, it cannot override specific
provisions of the bankruptcy code. Nor can a court
rewrite a confirmed plan on the grounds of perceived
equities.”). Airadigm and TDS dispute that the bank-
ruptcy court’s ruling is subject to the deference granted
“an interpretation” of a bankruptcy court order. They
claim that the bankruptcy court’s ruling did not “interpret”
14                                  Nos. 07-3863 & 07-3864

the plan but rather modified it and “rewrote history.”
The FCC argues to the contrary.
   After reviewing the record of the bankruptcy court, it
is clear to us that the bankruptcy court interpreted the
2000 plan when it found that the interest was implied.
The 2000 plan left several specifics of plan implement-
ation open for subsequent determination. When the plan
was confirmed, the legal status of Airadigm’s licenses
and the FCC’s automatic cancellation policy was still
pending. In allowing interest under § 1129(b)(2)(A), the
bankruptcy court revisited its own plan to interpret the
plan’s provisions in light of the changing status of the
licenses. The bankruptcy court reviewed the 2000 plan
and reviewed the contingencies related to whether the
FCC was to be treated as a secured or unsecured creditor.
It saw that the 2000 plan assumed that the FCC would
not be paid immediately on its allowed claim but would
receive deferred payments. It saw nothing in the 2000 plan
that specifically precluded interest under § 1129(b)(2)(A).
And it read the plan to imply that a § 1129(b) cram-down
would be required, and interest would be available, if
the FCC was ultimately found to be a secured creditor.
The bankruptcy court did not rewrite the plan so that it
would include a provision that was originally precluded.
Rather, the bankruptcy court’s grant of interest under
§ 1129(b)(2)(A) in this case was the result of a mere inter-
pretation of its own plan.
  The Sixth Circuit reached a similar conclusion in In re
Terex Corp., 984 F.2d 170 (6th Cir. 1993). In Terex, the
confirmed plan of reorganization provided that the
Nos. 07-3863 & 07-3864                                     15

debtor would pay insurance premiums upon a distribu-
tion date. The debtor failed to make the payments, and
the creditor-insurer filed a claim for the premiums
plus interest. The bankruptcy court held that the creditor
was entitled to interest from the effective date of the plan.
Terex, 984 F.2d at 171-72. On appeal, the debtor asserted
that interest was improperly awarded. Id. In affirming, the
Sixth Circuit rejected the debtor’s arguments that the
bankruptcy court’s order allowing interest contradicted
the terms of the plan and constituted an impermissible
modification. The Sixth Circuit found that the plan did not
explicitly preclude a retrospective award of interest, and
that the bankruptcy court’s decision was plausibly an
interpretation of the plan it had previously confirmed
pursuant to its equitable powers. Because it was an inter-
pretation, the bankruptcy court decision was entitled to
full deference on appeal. Id. at 172-73. The Terex case
supports our reasoning that the bankruptcy court was
engaged in an interpretation in the instant case.
  Like in Terex, the bankruptcy court’s finding here is
entitled to our full deference because it was an “interpreta-
tion” of its own reorganization plan. We have observed
that “[b]efore confirmation, a reorganization court must
approve the terms of a proposed plan to ensure that they
are ‘fair and equitable.’ Thus when a reorganization
court interprets a confirmed plan of reorganization, it
interprets words on which it has already passed judg-
ment. Under these circumstances, we believe that full
deference to the court’s decision is in order.” Chicago,
Milwaukee, St. Paul & Pacific R.R., 961 F.2d at 1264; see also
Weber, 25 F.3d at 416 (stating that because a bankruptcy
16                                 Nos. 07-3863 & 07-3864

court is uniquely situated to interpret its own order,
when it does so, that interpretation is subject to a highly
deferential standard of review). Under a full deference
standard, in order to overturn the interpretation, we
would need to determine there was an abuse of discretion
by the bankruptcy judge. Weber, 25 F.3d at 416. To the
contrary, we find it logical that the bankruptcy court
determined that the payment of interest was implied in
its order, as the bankruptcy court is uniquely situated to
interpret its own plan, and in this case it interpreted
its own plan to comply with a statutory scheme. There
was no abuse of discretion.
   Airadigm and TDS also argue that the “overriding error”
committed by the district court and the bankruptcy court
in granting implicit interest for the period between con-
firmation of the 2000 plan and commencement of the
2006 case was that “they disregarded the doctrine of
finality.” They claim that if the FCC believed it was
entitled to interest under § 1129(b), it should have
litigated that issue before confirmation of the plan or by
direct appeal, and that now the doctrine of res judicata
precludes the FCC from litigating the issue. This argument
fails under applicable Seventh Circuit precedent. In In re
Escobedo, 28 F.3d 34 (7th Cir. 1994), we held that a con-
firmed reorganization plan does not have res judicata
effect so as to bar a party from making an effort to bring
the plan into conformity with mandatory statutory provi-
sions. Escobedo, 28 F.3d at 35. As discussed, § 1129(b)
employs the word “requirement,” which signals that it is a
mandatory provision. It requires that an objecting, secured
creditor is paid interest if payment of the principal is
Nos. 07-3863 & 07-3864                                     17

deferred. 11 U.S.C. § 1129(b)(2)(A)(i)(II). The FCC’s
failure to assert its right to interest under § 1129(b)(2)(A)
before plan confirmation or on direct appeal does not
bar the FCC from asserting the right in this litigation.
  In sum, the FCC validly asserted its right to interest
under § 1129(b)(2)(A) in this litigation, and the bankruptcy
court interpreted its own plan to provide for such inter-
est. We defer to the bankruptcy court decision, and we
affirm that the FCC is entitled to interest for the time
period between confirmation of the 2000 plan and com-
mencement of the 2006 case.


C. July 28, 1999 to November 15, 2000
  An oversecured creditor’s entitlement to interest for the
period after the commencement of a case and before
confirmation of a plan is governed by § 506(b) of the
Bankruptcy Code, which states in pertinent part: “To the
extent that an allowed secured claim is secured by prop-
erty the value of which . . . is greater than the amount of
such claim, there shall be allowed to holder of such
claim, interest on such claim . . . .” 11 U.S.C. § 506(b). The
Code thus provides that the holder of an oversecured
claim is allowed post-petition interest to the extent of the
value of the collateral. Such interest accrues from the
petition date until the confirmation or effective date of
the plan, and the total amount of accrued, § 506(b) interest
is deemed an additional part of the secured creditor’s
allowed claim. Rake, 508 U.S. at 471-72.
  It is clear that the FCC had an oversecured claim for
the relevant time period, which lasted from July 28, 1999
18                                    Nos. 07-3863 & 07-3864

to November 15, 2000. The bankruptcy court did not
award § 506(b) interest to the FCC for this time period.
While it did not separately address this claim, it seems
to have denied this claim because it found the FCC’s claim
for post-1999 petition § 506(b) interest—which was
made well after its order on the OEDA objection that set
the FCC’s allowed claim at an amount that did not
account for interest—untimely. The district court reversed.
Our review of this issue, which is an issue of law, is
de novo.
  Airadigm and TDS argue on appeal that, by the time
the FCC first requested § 506(b) interest, the FCC had
already waived this claim. They argue that there is
nothing in the language of § 506(b) that allows a court to
award postpetition interest when the FCC did not
request § 506(b) interest prior to reorganization plan
confirmation; did not object to an allowance order that
did not award interest; and did not otherwise raise the
issue prior to the commencement of the 2006 case.
  In In re Chappell, 984 F.2d 775 (7th Cir. 1993), a Chapter 13
plan provided for the payment of an oversecured debt
in full, but the creditor neglected to request postpetition
interest under § 506(b). A year after confirmation of the
plan, the secured creditor contacted the Chapter 13 trustee
raising questions regarding whether interest had been
included in the debtor’s payment plans. However, the
secured creditor abandoned this effort before resolving
it and without bringing it to the bankruptcy court’s
attention. The case was closed four years later. Chappell,
984 F.2d at 778-82. Thereafter, a successor to the
secured creditor sought to collect interest on one of the
Nos. 07-3863 & 07-3864                                    19

oversecured claims. We recognized that both the bank-
ruptcy court and the district court found the creditor’s
belated request for interest was untimely: “Despite the
fact that section 506(b) may have entitled Homebanc [the
successor to the secured creditor] to interest, the courts
reasoned that Homebanc lost any entitlement when it
failed to raise this issue until after the Chapter 13 plan
had been completed, the Chappells discharged, and
the case closed.” Id. at 782. We affirmed. We stated:
“Several opportunities were available during the life of
the plan to assert the right to section 506(b) interest, but
none was taken. No objection was filed, and the plan
was confirmed. . . . As a general rule, the failure to raise
an objection at the confirmation hearing or to appeal
from the order of confirmation should preclude . . . attack
on the plan or any provision therein as illegal in a sub-
sequent proceeding.” Id. (internal citations omitted). We
continued: “It is important to note that Loves Park,
Homebanc’s predecessor, learned that it was not
receiving interest on the second mortgage while the
plan was still in effect. Yet, no effort was made to bring
this fact to the attention of the bankruptcy court. Instead,
Homebanc sought relief only after the Chappells were
discharged and the case was closed.” Id. at 783.
  In the instant case, the FCC did not assert its right to
§ 506(b) interest at any point before the bankruptcy court
“closed” the 1999 case. But, the 1999 case was “substan-
tially consummated” and “closed” only because the
parties reached an agreement to preserve the 1999 claims
as part of the 2006 case. Before agreeing to the close of the
1999 case, the FCC and Airadigm explicitly stipulated
20                                  Nos. 07-3863 & 07-3864

that “[t]he FCC’s allowed claim in the 1999 bankruptcy
case shall be allowed in the 2006 bankruptcy case,” and
that “all other rights of the parties hereto (including
without limitation, the right of the FCC and TDS to
seek inclusion and allowance of interest on their allowed
claims) . . . are expressly reserved.” In exchange for this
agreement, the FCC agreed not to object to the closing
of the 1999 case and the opening of the 2006 case.
   The stipulation distinguishes the instant case from
Chappell. We based our decision in Chappell largely on the
fact that the bankruptcy case was closed and the
creditor’s principal was paid in full. Here the 1999 claims
were not “closed,” and Airadigm was not discharged
from bankruptcy when the FCC requested the interest.
Chappell does not stand for the proposition that failure
to assert the right to § 506(b) interest before plan con-
firmation waives that right, and it would be illogical for
us to hold here that the FCC needed to request § 506(b)
interest before plan confirmation to avoid waiver. Section
506(b) interest is only available to oversecured creditors,
and while the FCC could have known that the licenses
were worth more than the amount of its claim at the time
of confirmation, it was unclear whether the FCC was a
secured or unsecured creditor at that time. While it
would have been prudent for the FCC to request § 506(b)
interest sooner after the licenses were reinstated, the right
to request such interest was not waived. To the contrary,
the 1999 claims were expressly preserved as a result of
the FCC’s diligence in protecting its rights while waiting
for the debtor to pay its debt.
Nos. 07-3863 & 07-3864                                 21

  Thus, § 506(b) entitles the FCC to interest accruing
from July 28, 1999 to November 15, 2000. We affirm the
district court’s award of postpetition interest for the
interim period between commencement of the 1999
bankruptcy proceeding and confirmation of the 2000
reorganization plan.


                    III. Conclusion
  For the foregoing reasons, we A FFIRM the district
court’s ruling awarding post-confirmation interest for the
period between confirmation of Airadigm’s 2000 plan of
reorganization and commencement of new bankruptcy
proceedings in 2006; and we A FFIRM the district court’s
award of post-petition interest for the interim period
between commencement of the 1999 bankruptcy pro-
ceeding and confirmation of the 2000 plan.




                         10-29-08
