                    FOR PUBLICATION

   UNITED STATES COURT OF APPEALS
        FOR THE NINTH CIRCUIT


 UNITED STATES OF AMERICA,                        No. 18-17036
                Petitioner-Appellee,
                                                    D.C. No.
                     v.                          3:15-cv-00092-
                                                     WHA
 SANMINA CORPORATION AND
 SUBSIDIARIES,
               Respondent-Appellant.                OPINION

        Appeal from the United States District Court
          for the Northern District of California
         William Alsup, District Judge, Presiding

          Argued and Submitted February 11, 2020
                 San Francisco, California

                      Filed August 7, 2020

Before: Johnnie B. Rawlinson and Consuelo M. Callahan,
  Circuit Judges, and Susan R. Bolton,* District Judge.

                  Opinion by Judge Callahan




    *
      The Honorable Susan R. Bolton, United States District Judge for
the District of Arizona, sitting by designation.
2             UNITED STATES V. SANMINA CORP.

                          SUMMARY **


                                 Tax

    The panel affirmed in part and reversed in part the
district court’s determination, that taxpayer Sanmina
Corporation had waived attorney-client privilege and work-
product protection for certain memoranda prepared in
support of a worthless stock deduction on Sanmina’s federal
tax return, in a petition by the Internal Revenue Service to
enforce a summons for those memoranda.

    The memoranda in question (Attorney Memos) were
authored by Sanmina’s in-house counsel and referenced in a
valuation report prepared by DLA Piper (DLA Piper Report)
in support of the worthless stock deduction. The district
court initially denied enforcement of the summons. This
court remanded for in camera review of the Attorney
Memos. On remand, the district court determined that the
Attorney Memos were covered by both attorney-client
privilege and work-product protection, but that those
privileges had been waived. On appeal, the parties did not
dispute that the Attorney Memos were privileged.

    The panel first held that Sanmina expressly waived the
attorney-client privilege when it disclosed the Attorney
Memos to DLA Piper. The panel next held that Sanmina did
not expressly waive work-product immunity merely by
providing the Attorney Memos to DLA Piper, but it
impliedly waived the privilege when it subsequently used the

    **
       This summary constitutes no part of the opinion of the court. It
has been prepared by court staff for the convenience of the reader.
            UNITED STATES V. SANMINA CORP.                  3

DLA Piper Report to support its tax deduction in an IRS
audit, because such use was inconsistent with the
maintenance of secrecy against its adversary. The panel
ordered disclosure of only the factual content of the Attorney
Memos on which the DLA Piper Report relies, and
remanded for the district court to determine the specific
portions of the Attorney Memos that should be disclosed to
the IRS.


                        COUNSEL

Michael C. Lieb (argued) and Leemore L. Kushner, Ervin
Cohen & Jessup LLP, Beverly Hills, California, for
Respondent-Appellant.

Bethany B. Hauser (argued) and Deborah K. Snyder,
Attorneys; Richard E. Zuckerman, Principal Deputy
Assistant Attorney General; Tax Division, United States
Department of Justice, Washington, D.C.; for Petitioner-
Appellee.
4            UNITED STATES V. SANMINA CORP.

                          OPINION

CALLAHAN, Circuit Judge:

    Sanmina Corporation (“Sanmina”) claimed a worthless
stock deduction on its federal tax return, which triggered an
audit by the United States Internal Revenue Service (“IRS”)
of Sanmina’s tax returns. To support the deduction,
Sanmina provided to the IRS a valuation report that had been
prepared by DLA Piper, LLP, which in turn cited two
memoranda authored by Sanmina in-house counsel. The
IRS issued a summons for the memoranda, and Sanmina
objected on the basis that they were protected both by
attorney-client privilege and the attorney work-product
doctrine.

    After the district court initially denied enforcement of the
summons, the IRS appealed to this court. We remanded for
in camera review of the memoranda but retained jurisdiction
over the appeal. United States v. Sanmina, 707 F. App’x 865
(9th Cir. 2017). On remand, the district court determined
that the memoranda were covered by both attorney-client
privilege and work-product protection, but that those
privileges had been waived.

    We affirm in part and reverse in part the district court’s
findings. We agree that Sanmina’s disclosure of the
memoranda to DLA Piper waived the attorney-client
privilege. However, such disclosure did not waive their
work-product protection, except for the factual content of the
memoranda. Accordingly, we grant in part and deny in part
the IRS’s enforcement petition, and remand to the district
court to issue a disclosure order consistent with this opinion.
            UNITED STATES V. SANMINA CORP.                 5

                             I.

    In its federal tax return, Sanmina claimed a worthless
stock deduction arising from its ownership of shares of stock
in a Swiss subsidiary, Sanmina International AG (“Sanmina
AG,” also referred to internally as “Swiss-3600”). The
deduction totaled $503 million and offset all of Sanmina’s
taxable income for the 2008 tax year, with carryforward
losses. The IRS subsequently initiated an examination of
Sanmina’s federal income tax liabilities of Sanmina
Corporation and subsidiaries for the 2008, 2009, and 2010
taxable periods.

    To support the worthless stock deduction, Sanmina
provided the IRS with a valuation report prepared by DLA
Piper (the “DLA Piper Report”), which referred to two
memoranda authored by Sanmina’s in-house counsel (the
“Attorney Memos”) in a footnote of the report. The IRS then
issued a summons for the Attorney Memos. In response,
Sanmina declined to produce the memoranda, invoking
attorney-client privilege and attorney work-product
protection. However, Sanmina agreed to disclose to the IRS
the “non-privileged documents on which the analyses
contained in the [Attorney Memos] are based.”

                             A.

    The DLA Piper Report is 102 pages and titled on the
cover page as “Sanmina-SCI Corporation – Estimate of Fair
Market Value of Sanmina International AG – Valuation as
of June 30, 2009.” Each page contains the label “Attorney-
Client Privilege – Confidential Draft.” The report begins
with a two-page letter, which is addressed to Sanmina’s in-
house counsel, and signed by a DLA Piper partner and
economist. It states in part:
6           UNITED STATES V. SANMINA CORP.

       DLA Piper . . . has concluded a fair market
       value (“FMV”) analysis supporting your
       assessment of insolvency of Sanmina
       International AG . . . . We understand our
       summary report will be used solely for tax
       compliance purposes, specifically for
       confirming the worthlessness of Sanmina
       International AG’s common shares. Our
       estimate of value does not constitute a
       fairness opinion or an estimate of FMV for
       any other purpose and should not be relied
       upon as such.

The two-page letter concludes: “Based on a combination of
DCF and ANA analyses, we estimate the FMV of a
marketable, controlling interest in Sanmina AG to be a
negative US$49 million as of the Valuation Date. The value
of Subject Company’s cumulative liabilities therefore
exceeded the value of its assets by US$49 million.”

   In the report’s Executive Summary, a section headlined
“Nature of Engagement” states:

       Sanmina . . . has asked DLA Piper . . . to
       provide an estimate of the fair market value
       (“FMV”) of 100 percent of the common stock
       of its wholly-owned subsidiary . . . . as of
       June 30, 2009 (“Valuation Date”). We
       understand that this analysis will be used by
       Sanmina’s management (“Management”) to
       make a determination of value on liquidation
       of Subject Company as of the Valuation Date
       in the context of a restructuring of Sanmina’s
       international operations. In this content [sic],
       it is Management’s intent to assess whether
            UNITED STATES V. SANMINA CORP.               7

       Sanmina AG’s common stock as of the
       Valuation Data [sic] was worthless.
       Furthermore, it is our understanding that
       Sanmina will not disclose our analysis to
       third parties other than its financial auditors
       and interested tax authorities without our
       expressed written consent.

    The footnote referencing the Attorney Memos is found
on page 56 of the report within the following paragraph:

       We believed that the book value of each
       liability provides the best estimation of its
       FMV. However, based on interviews with
       Management and related documents
       provided by Management,6 we concluded
       that the intercompany loan between Sanmina
       Holding AB and Sanmina Kista (about
       US$ 90 million) as well as the intercompany
       non-trade receivable between Sanmina-SCI
       and Sanmina AG [i.e., Swiss 3600] (about
       US$ 113 million) should be disregarded.

In the text of footnote 6 above, three documents are listed
without further explanation: (1) “Memo draft: Stock and
Debt Losses on Swiss-3600, March 11, 2009”; (2) “Capital
Contribution Agreement between Sanmina-SCI Corporation
and Sanmina International AG, July 3, 2006; and
(3) “Memo: Guarantee and Capital Contribution Agreement
Concerning Sanmina International AG, July 2, 2006.” The
first and third documents listed are the Attorney Memos at
issue in this case.
8          UNITED STATES V. SANMINA CORP.

                            B.

   The Attorney Memos are described by Sanmina’s in-
house counsel as follows:

      The 2006 Attorney Memo is a memorandum
      dated July 2, 2006 from a former Sanmina tax
      department attorney named Chris Croudace
      to “File.” The memorandum discusses the
      legal analysis supporting the execution of
      certain agreements among Sanmina and its
      subsidiaries, including the reason for those
      agreements, their legal enforceability, and
      their tax treatment.      The memorandum
      includes citations to, and analysis of certain
      IRS letter rulings and two tax court decisions.

      . . . The 2009 Attorney Memo is a draft
      memorandum dated March 11, 2009. The
      name of the author is not apparent from the
      face of the document, but I was able to
      ascertain that the author is Mark L. Johnson,
      a former Sanmina tax department lawyer.
      Each page of the document bears the notation
      “Confidential – Work Product Privilege.”
      The 2009 Attorney Memo analyzes the tax
      effect of the liquidation of “Swiss-3600,”
      which is Sanmina’s internal designation for
      Sanmina International AG.           The 2009
      Attorney Memo contains a factual discussion
      and the bulk of the memo consists of a legal
      analysis of those facts and their effect on the
      liquidation of Swiss-3600. It cites IRS
      revenue rulings, tax code provisions, tax
            UNITED STATES V. SANMINA CORP.                  9

       court decisions, and a decision of the U.S.
       Supreme Court.

A privilege log produced by Sanmina demonstrates that the
Attorney Memos were shared outside of Sanmina only with
Ernst & Young, KPMG, LLP, and DLA Piper. Sanmina’s
Director of Tax Controversy and Tactical Support, Brian
Dulkie, explains in an affidavit that the Attorney Memos
were “were provided to Ernst & Young . . . and KPMG to
support Sanmina’s taking of a worthless stock deduction”
and both those firms “provided tax advice related to
Sanmina’s decision to take the worthless stock.” According
to Dulkie:

       Given the significance of that tax treatment,
       Sanmina proceeded with the expectation that
       IRS would likely call upon Sanmina to
       defend the worthless stock deduction.
       Anticipating the possibility that the Service
       might adopt an adverse position, Sanmina
       sought advice from DLA Piper, Ernst &
       Young and KPMG concerning the propriety
       of the deduction.

                             C.

    In January 2015, the IRS filed a petition to enforce the
summons for the Attorney Memos, and the district court
issued an order to show cause to Sanmina. After briefing
from the parties and a hearing, the district court (Magistrate
Judge Paul S. Grewal) issued an order denying enforcement
of the summons, finding that the memoranda were privileged
and that the privileges were not waived. The IRS appealed.

    In December 2017, a panel of this court remanded the
case “for the district court to review the 2006 and 2009
10           UNITED STATES V. SANMINA CORP.

memos in camera to determine whether the documents
requested by the government are privileged to any degree”
and “retain[ed] jurisdiction over this appeal.” Sanmina,
707 F. App’x at 866. In June 2018, after some dispute
between the parties regarding the scope of the remand and a
request for clarification from the district court, this court
issued another order defining the scope of remand as:
(1) whether the memoranda are privileged in the first
instance and (2) whether such privilege was waived.

                              D.

     On remand, the district court (Judge William H. Alsup)
issued an order that affirmed “Judge Grewal’s finding that
the memoranda are protected by the attorney-client privilege
and attorney work-product doctrine,” but found that the
privileges were “waived when Sanmina disclosed the
memoranda to DLA Piper to obtain an opinion on value, then
turned over the valuation report to the IRS.” Based on its in
camera review of the memoranda, the court found that they
were protected both by (1) attorney-client privilege because
“Sanmina sufficiently showed that the memoranda were
prepared by in-house counsel, in response to a request for
legal advice, and contain legal advice communicated in
confidence to Sanmina executives” and (2) attorney work-
product doctrine because “while there was no pending
litigation when the memoranda were drafted, Sanmina
reasonably anticipated that the IRS would scrutinize its
$503 million stock deduction, so it engaged in-house
counsel to analyze the consequences of taking such a
deduction.”

     As to waiver, the district court concluded:

        Any attorney-client privilege that might have
        attached to the memoranda was waived when
            UNITED STATES V. SANMINA CORP.                 11

       Sanmina       voluntarily    disclosed     the
       memoranda to DLA Piper, not for the
       purpose of receiving legal advice, but for the
       purpose of determining the value of Sanmina
       AG’s common stock. Sanmina engaged
       DLA Piper for the purpose of conducting a
       fair market value analysis to be used for tax
       compliance reasons. Anticipating that the
       IRS would adopt an “adverse position” to
       taking a $500 million deduction, Sanmina
       sought DLA Piper’s services in producing the
       valuation report. Thus, the point of waiver
       took place when Sanmina provided the
       privileged memoranda to DLA Piper for the
       purpose of producing a valuation report to
       then turn over to the IRS. Sanmina cannot
       disclose a privileged attorney communication
       relevant to an issue of material fact, then
       invoke      privilege     to    shield    that
       communication from discovery.

The district court did not conduct a separate analysis for
waiver of work-product protection apart from its discussion
of waiver for attorney-client privilege but relied on Weil v.
Investment/Indicators, Research & Management, Inc.,
647 F.2d 18 (9th Cir. 1981), as “the controlling decision in
our circuit” for both issues.

    Although its conclusion that waiver occurred when
Sanmina disclosed the Attorney Memos to DLA Piper was
“dispositive” of the waiver question, the district court also
alternatively held that “Sanmina’s disclosure of the DLA
Piper valuation report to the IRS waived any applicable
privilege as to materials used to reach the valuation.” Citing
Fed. R. Evid. § 502(a)(3), the district court reasoned that
12          UNITED STATES V. SANMINA CORP.

because “DLA Piper’s valuation report relied on the contents
of the memoranda” and “based its conclusions, at least in
part, on the two memoranda at issue,” “[t]he analyses that
informed the valuation report’s conclusions should, in
fairness, be considered together.” The court rejected
Sanmina’s argument “that the footnote merely disclosing the
existence of the memoranda did not waive any applicable
privilege as to their entire contents,” reiterating that “it
would be fundamentally unfair for Sanmina to disclose the
valuation report while withholding its foundation.”

                             II.

    The district court found—and the parties do not
dispute—that the Attorney Memos constituted both
privileged attorney-client communications and protected
attorney work product. Thus, the only issue before us is the
question of waiver—specifically, whether Sanmina waived
attorney-client privilege or work-product protection by
providing the memoranda to DLA Piper and providing the
DLA Piper Report to the IRS. Because the Attorney Memos
constitute attorney-client communications and protected
attorney work product, we must find that Sanmina waived
both privileges to mandate disclosure of the memoranda.

    Whether a privilege has been waived is a mixed question
of fact and law that we review de novo. United States v.
Plache, 913 F.2d 1375, 1379 (9th Cir. 1990); United States
v. Mendelsohn, 896 F.2d 1183, 1188 (9th Cir. 1990). We
review for clear error a district court’s factual findings for
attorney-client privilege and work-product doctrine. See
United States v. Richey, 632 F.3d 559, 563–64 (9th Cir.
2011). “A finding is clearly erroneous if it is illogical,
implausible, or without support in the record.” United States
v. Graf, 610 F.3d 1148, 1157 (9th Cir. 2010).
            UNITED STATES V. SANMINA CORP.                 13

                             III.

                             A.

    The attorney-client privilege protects confidential
communications between attorneys and clients, which are
made for the purpose of giving legal advice. Upjohn Co. v.
United States, 449 U.S. 383, 389 (1981). Whether
information is covered by the attorney-client privilege is
determined by an eight-part test:

       (1) Where legal advice of any kind is sought
       (2) from a professional legal adviser in his
       capacity as such, (3) the communications
       relating to that purpose, (4) made in
       confidence (5) by the client, (6) are at his
       instance permanently protected (7) from
       disclosure by himself or by the legal adviser,
       (8) unless the protection be waived.

Graf, 610 F.3d at 1156.

    “The attorney-client privilege may extend to
communications with third parties who have been engaged
to assist the attorney in providing legal advice,” Richey,
632 F.3d at 566, as well as to communications with third
parties “acting as agent” of the client. United States v.
Landof, 591 F.2d 36, 39 (9th Cir. 1978). “If the advice
sought is not legal advice, but, for example, accounting
advice from an accountant, then the privilege does not exist.”
Richey, 632 F.3d at 566 (citation omitted). Thus, we have
recognized several contexts in which communications with
attorneys for the purpose of non-legal advice are not
14             UNITED STATES V. SANMINA CORP.

privileged. 1 In general, however, “[i]f a person hires a
lawyer for advice, there is a rebuttable presumption that the
lawyer is hired ‘as such’ to give ‘legal advice,’ whether the
subject of the advice is criminal or civil, business, tort,
domestic relations, or anything else.” United States v. Chen,
99 F.3d 1495, 1501 (9th Cir. 1996). This “presumption is
rebutted when the facts show that the lawyer was ‘employed
without reference to his knowledge and discretion in the
law.’” Id.

    There are “several ways by which parties may waive the
privilege.” In re Pac. Pictures Corp., 679 F.3d 1121, 1126
(9th Cir. 2012) (citations omitted). First, “voluntarily
disclosing privileged documents to third parties will
generally destroy the privilege.” Id. at 1126–27. Also
known as an “express waiver,” this type of waiver “occurs
when a party discloses privileged information to a third party
who is not bound by the privilege, or otherwise shows
disregard for the privilege by making the information
public.” Bittaker v. Woodford, 331 F.3d 715, 719 (9th Cir.
2003). “Disclosures that effect an express waiver are
typically within the full control of the party holding the
privilege; courts have no role in encouraging or forcing the



     1
       See, e.g., United States v. Rowe, 96 F.3d 1294, 1297 (9th Cir. 1996)
(noting “[w]here the attorney was asked for business (as opposed to
legal) counsel, no privilege attached,” but “fact-finding which pertains
to legal advice counts as ‘professional legal services’” (citations
omitted)); United States v. Huberts, 637 F.2d 630, 640 (9th Cir. 1980)
(“Generally, an attorney who serves as a business agent to a client may
not assert the attorney-client privilege, because no confidential
relationship attaches.”); see also Harris v. United States, 413 F.2d 316,
320 (9th Cir. 1969) (applying “the general rule that ministerial or clerical
services performed by an attorney are not within the privilege”).
            UNITED STATES V. SANMINA CORP.                 15

disclosure—they merely recognize the waiver after it has
occurred.” Id.

    In contrast, waiver by implication, or implied waiver, is
based on the rule that “a litigant waives the attorney-client
privilege by putting the lawyer’s performance at issue during
the course of litigation.” Id. at 718; see also Weil, 647 F.2d
at 24 (“[T]he federal cases presuppose that waiver may be
effected by implication.”). Waivers by implication rest on
the “fairness principle,” which

       is often expressed in terms of preventing a
       party from using the privilege as both a shield
       and a sword. . . . In practical terms, this
       means that parties in litigation may not abuse
       the privilege by asserting claims the opposing
       party cannot adequately dispute unless it has
       access to the privileged materials.

Bittaker, 331 F.3d at 719 (citation omitted).

    This fairness principle also animates the concept of
subject matter waiver, in which “voluntary disclosure of the
content of a privileged attorney communication constitutes
waiver of the privilege as to all other such communications
on the same subject.” Weil, 647 F.2d at 24; see also Plache,
913 F.2d at 1380 (finding disclosure of a privileged
communication waived the privilege “on all other
communications on the same subject”). Under this rule,
“disclosure of information resulting in the waiver of the
attorney-client privilege constitutes waiver ‘only as to
communications about the matter actually disclosed.’”
Chevron Corp. v. Pennzoil Co., 974 F.2d 1156, 1162 (9th
Cir. 1992) (quoting Weil, 647 F.2d at 25)); see also
Mendelsohn, 896 F.2d at 1189 (affirming decision confining
testimony based on waiver to the subject of the waiver).
16           UNITED STATES V. SANMINA CORP.

                              B.

    Whether Sanmina expressly waived the attorney-client
privilege over the Attorney Memos by voluntarily disclosing
them to DLA Piper turns chiefly on whether Sanmina shared
the memoranda with DLA Piper for the purpose of obtaining
legal advice. If Sanmina did not engage DLA Piper for its
legal services, as the district court found, then DLA Piper
was properly treated as a third party for the purposes of
attorney-client privilege, and Sanmina’s disclosure of the
memos to DLA Piper expressly waived the privilege. On the
other hand, if Sanmina shared the memoranda with DLA
Piper in order to secure legal advice, as Sanmina asserts, then
these privileged communications were maintained within a
confidential relationship between Sanmina and DLA Piper.

    In finding that Sanmina disclosed the Attorney Memos
to DLA Piper for a non-legal purpose, the district court
reasonably relied on language from the DLA Piper Report
and Dulkie’s statement indicating that “Sanmina engaged
DLA Piper for the purpose of conducting a fair market value
analysis to be used for tax compliance reasons” and “sought
DLA Piper’s services in producing the valuation report.”
These same evidentiary sources, however, also provide
inferential support for Sanmina’s claim that it engaged DLA
Piper as outside tax counsel and shared the privileged
memoranda for the purpose of obtaining DLA Piper’s legal
advice. For instance, Dulkie’s statement that “Sanmina
sought advice from DLA Piper . . . concerning the propriety
of the [tax] deduction” after “[a]nticipating that the [IRS]
might adopt an adverse position” could reasonably support
the conclusion that the advice Sanmina sought from DLA
Piper regarding the propriety of its tax deduction was legal
                UNITED STATES V. SANMINA CORP.                           17

in nature. 2 The DLA Piper Report also provides some
indications of an attorney-client relationship, or at least an
expectation of attorney-client confidentiality, between DLA
Piper and Sanmina. 3

    Viewed in its entirety, the record might suggest that
Sanmina shared the Attorney Memos with DLA Piper for the
purpose of seeking both legal and non-legal advice
pertaining to the propriety of its tax deduction.
Communications made for such a “dual purpose” are not
uncommon in the tax law context, where an attorney’s
advice may integrally involve both legal and non-legal
analyses. 4 While our court has not yet addressed how to

    2
       While Dulkie does not explicitly describe the advice sought as
“legal,” such an inference would not be unreasonable given the
undisputed fact that DLA Piper is a law firm, which comes with a
“rebuttable presumption” that the firm was engaged for its legal
knowledge. See Chen, 99 F.3d at 1502 (stating that where “attorneys
were employed for their legal knowledge, to bring their clients into
compliance with the law . . . [t]heir communications with their clients
were . . . within the scope of the attorney-client privilege”).
    3
       For instance, the cover letter of the DLA Piper Report was
addressed to Sanmina’s in-house counsel and stated that DLA Piper had
conducted a valuation analysis “supporting your assessment of
insolvency of Sanmina International AG,” which could be interpreted as
evidence that Sanmina engaged DLA Piper to review and verify its in-
house legal analysis on the insolvency of its subsidiary and its potential
tax implications. The report was also signed, in part, by a firm attorney
and contains “attorney-client privilege” warnings on each page, which
could indicate an understanding between DLA Piper and Sanmina that
its shared documents and communications were covered by attorney-
client confidentiality.
    4
      See 1 Paul R. Rice, Attorney-Client Privilege in the United States
§ 7:4 (2019) (“In a broad range of areas (e.g., tax, commercial, patent,
criminal, or litigation and its avoidance), ‘legal’ assistance often involves
18             UNITED STATES V. SANMINA CORP.

assess when a “dual purpose” communication remains
within the privilege, we recognize that district courts in our
circuit have grappled with this question and differed in
regard to the proper test to apply. 5 Notwithstanding this
intra-circuit split, however, we need not decide the issue on
the facts of this case. Despite some evidence that Sanmina
may have had a “dual purpose” for sharing the Attorney
Memos to DLA Piper, the district court’s finding that
Sanmina’s purpose was to obtain a non-legal valuation

many non-legal, complementary services.”); United States v. Cote,
456 F.2d 142, 144 (8th Cir. 1972) (holding that an accountant’s work
papers used by the attorney in advising client were privileged where the
attorney’s “decision as to whether the taxpayers should file an amended
return undoubtedly involved legal considerations which mathematical
calculations alone would not provide” and “the accountant’s aid to the
lawyer preceded the advice and was an integral part of it.”); In re Grand
Jury Subpoena Duces Tecum Dated Sept. 15, 1983, 731 F.2d 1032, 1037
(2d Cir. 1984) (“Tax advice rendered by an attorney is legal advice
within the ambit of the privilege.”).

     5
       Some district courts have applied a “primary purpose” test. See,
e.g., Phillips v. C.R. Bard, Inc., 290 F.R.D. 615, 628 (D. Nev. 2013);
U.S. v. Salyer, 853 F. Supp. 2d 1014, 1018 (E.D. Cal. 2012); Premiere
Digital Access, Inc. v. Central Telephone Co., 360 F. Supp. 2d 1168,
1174 (D. Nev. 2005); United States v. ChevronTexaco Corp., 241 F.
Supp. 2d 1065, 1076 (N.D. Cal. 2002). Other courts have transported
the “because of” test from the work-product context, and looked to “the
totality of the circumstances” to determine “the extent to which the
communication solicits or provides legal advice or functions to facilitate
the solicitation or provision of legal advice.” See In re CV Therapeutics,
Inc. Sec. Litig., No. C-03-3709 SI(EMC), 2006 WL 1699536, at *3–4
(N.D. Cal. June 16, 2006); Visa U.S.A., Inc. v. First Data Corp., No. C-
02-1786JSW(EMC), 2004 WL 1878209, at *4 (N.D. Cal. Aug. 23, 2004)
(“The Court discerns no reason why . . . for purposes of determining the
discoverability of documents that have both a legal purpose and a
nonlegal purpose (e.g., business purpose), the [“because of”]
methodology in In re Grand Jury Subpoena[, 357 F.3d 900 (9th Cir.
2004),] should not be applied to the attorney-client privilege.”).
             UNITED STATES V. SANMINA CORP.                 19

analysis from DLA Piper, rather than legal advice, was not
clearly erroneous because it was not “illogical, implausible,
or without support in the record.” Graf, 610 F.3d at 1157.
Because its factual findings do not rise to clear error, we
affirm the district court’s conclusion that Sanmina expressly
waived attorney-client privilege over the Attorney Memos
when it disclosed the memos to DLA Piper.

    Given our conclusion that Sanmina expressly waived
attorney-client privilege over the Attorney Memos when
they were disclosed to DLA Piper, we need not reach
whether Sanmina also waived the privilege when it provided
the DLA Piper Report to the IRS based on the fairness
principle. But our inquiry is not over. Because we agree
with the district court that the Attorney Memos constituted
both privileged attorney-client communications as well as
protected work product, we turn next to whether Sanmina
also waived work-product protection over the memoranda.

                             IV.

                              A.

     The work-product doctrine is a “qualified” privilege that
protects “from discovery documents and tangible things
prepared by a party or his representative in anticipation of
litigation.” Admiral Ins. Co. v. U.S. Dist. Ct., 881 F.2d 1486,
1494 (9th Cir. 1989) (citing Fed. R. Civ. P. 26(b)(3)); see
also United States v. Nobles, 422 U.S. 225, 237–38 (1975).
“At its core, the work-product doctrine shelters the mental
processes of the attorney, providing a privileged area within
which he can analyze and prepare his client’s case,” and
protects both “material prepared by agents for the attorney
as well as those prepared by the attorney himself.” Nobles,
422 U.S. at 238–39. The primary purpose of the work-
20           UNITED STATES V. SANMINA CORP.

product rule is to “prevent exploitation of a party’s efforts in
preparing for litigation.” Admiral Ins. Co., 881 F.2d at 1494.

    “The privilege derived from the work-product doctrine
is not absolute. Like other qualified privileges, it may be
waived.” Nobles, 422 U.S. at 239. Similar to the waiver of
the attorney-client privilege, a litigant can waive work-
product protection to the extent that he reveals or places the
work product at issue during the course of litigation. For
instance, in Nobles, a criminal defendant’s decision to
present his defense investigator as a witness waived work-
product privilege over the investigator’s report “with respect
to matters covered in his testimony.” Id. at 236, 239.
Similarly, in Hernandez v. Tanninen, 604 F.3d 1095, 1100
(9th Cir. 2010), a party’s production of an attorney’s notes
in support of his opposition to a motion constituted a waiver
of work-product privilege over the subject matter of the
notes disclosed.

    Both parties posit that, unlike waivers by disclosure in
the attorney-client privilege context, waivers of work-
product protection require disclosing the work product to an
adversary, and not merely to a third party. While the parties
do not provide us a controlling decision for this proposition,
we have nonetheless recognized that “there is an important
distinction between the rules governing when each type of
protection has been waived.” Transamerica Computer Co.,
Inc. v. Int’l Bus. Machines Corp., 573 F.2d 646, 647 n.1 (9th
Cir. 1978). Although we did not further elaborate on this
“important distinction” in Transamerica Computer, 6 we


     6
      We found the distinction between the two types of waiver
“unimportant” in Transamerica Computer because there, “the third
person to whom the disclosure was made, a disclosure supposedly
             UNITED STATES V. SANMINA CORP.                     21

cited a number of authorities expressing the principle that
waiver of attorney-client privilege by disclosure to a third
party “does not necessarily affect the work product
protection since the two are designed to accomplish different
results.” Ceco Steel Prod. Corp. v. H. K. Porter Co., 31
F.R.D. 142, 143 (N.D. Ill. 1962); see also Vilastor-Kent
Theatre Corp. v. Brandt, 19 F.R.D. 522, 524 (S.D.N.Y.
1956)).

    Since our decision in Transamerica, courts appear to
have reached a general “uniformity in implying that work-
product protection is not as easily waived as the attorney-
client privilege” based on the distinct purposes of the two
privileges. United States v. Mass. Inst. of Tech., 129 F.3d
681, 687 (1st Cir. 1997). While the attorney-client privilege
“is designed to protect confidentiality, so that any disclosure
outside the magic circle is inconsistent with the privilege,”
work-product protection “is provided against ‘adversaries,’
so only disclosing material in a way inconsistent with
keeping it from an adversary waives work product
protection.” Id.; see also United States v. Deloitte LLP,
610 F.3d 129, 140 (D.C. Cir. 2010) (“Voluntary disclosure
waives the attorney-client privilege because it is inconsistent
with the confidential attorney-client relationship. Voluntary
disclosure does not necessarily waive work-product
protection, however, because it does not necessarily
undercut the adversary process.”).           Accordingly, the
overwhelming majority of our sister circuits have espoused
or acknowledged the general principle that the voluntary
disclosure of work product waives the protection only when
such disclosure is made to an adversary or is otherwise
inconsistent with the purpose of work-product doctrine—to

resulting in a waiver, was IBM’s adversary in litigation.” 573 F.2d
at 647 n.1.
22              UNITED STATES V. SANMINA CORP.

protect the adversarial process. 7 District courts in our circuit
have also applied the same principle. 8


     7
       See, e.g., Mass. Inst. of Tech., 129 F.3d at 687 (“[O]nly disclosing
material in a way inconsistent with keeping it from an adversary waives
work product protection.”); In re Steinhardt Partners, L.P., 9 F.3d 230,
235 (2d Cir. 1993) (“[V]oluntary disclosure of work product to an
adversary waives the privilege as to other parties.”); In re Chevron
Corp., 633 F.3d 153, 165 (3rd Cir. 2011) (“[I]t is only in cases in which
the material is disclosed in a manner inconsistent with keeping it from
an adversary that the work-product doctrine is waived.”); Ecuadorian
Plaintiffs v. Chevron Corp., 619 F.3d 373, 378 (5th Cir. 2010)
(“Although work product immunity is not automatically waived by
disclosure of protected material to third parties, disclosure does waive
protection if it ‘has substantially increased the opportunities for potential
adversaries to obtain the information.’” (citation omitted)); In re
Columbia/HCA Healthcare Corp. Billing Practices Litig., 293 F.3d 289,
306 (6th Cir. 2002) (“Other than the fact that the initial waiver must be
to an ‘adversary,’ there is no compelling reason for differentiating waiver
of work product from waiver of attorney-client privilege.” (footnote
omitted)); In re Chrysler Motors Corp. Overnight Evaluation Program
Litig., 860 F.2d 844, 846 (8th Cir. 1988) (“Disclosure to an adversary
waives the work product protection as to items actually disclosed . . . .”
(internal quotation marks and citation omitted)); Doe No. 1 v. United
States, 749 F.3d 999, 1008 (11th Cir. 2014) (“Disclosure of work-
product materials to an adversary waives the work-product privilege.”);
United States v. Am. Tel. & Tel. Co., 642 F.2d 1285, 1299 (D.C. Cir.
1980) (“[D]isclosure to a third party does not waive the privilege ‘unless
such disclosure, under the circumstances, is inconsistent with the
maintenance of secrecy from the disclosing party's adversary.’”); Carter
v. Gibbs, 909 F.2d 1450, 1451 (Fed. Cir. 1990) (“Voluntary disclosure
of attorney work product to an adversary in the litigation for which the
attorney produced that information defeats the policy underlying the
privilege . . . .”).

     8
       See, e.g., Samuels v. Mitchell, 155 F.R.D. 195, 200 (N.D. Cal.
1994) (“[T]he work product privilege is not automatically waived by any
disclosure to third persons. Rather, the courts generally find a waiver
only if the disclosure ‘substantially increases the opportunity for
               UNITED STATES V. SANMINA CORP.                         23

    Thus, consistent with our sister circuits as well as
precedent on the unique purposes for the work-product
doctrine, we hold that disclosure of work product to a third
party does not waive the protection unless such disclosure is
made to an adversary in litigation or “has substantially
increased the opportunities for potential adversaries to
obtain the information.” 8 Charles Alan Wright & Arthur R.
Miller, Federal Practice & Procedure § 2024 (3d ed. 2020).
Put another way, disclosing work product to a third party
may waive the protection where “such disclosure, under the
circumstances, is inconsistent with the maintenance of
secrecy from the disclosing party’s adversary.” Rockwell
Int’l Corp. v. U.S. Dep’t of Justice, 235 F.3d 598, 605 (D.C.
Cir. 2001) (internal quotation marks and citation omitted).
“Under this standard, the voluntary disclosure of attorney
work product to an adversary or a conduit to an adversary
waives work-product protection for that material.” Deloitte,
610 F.3d at 140.

    In Deloitte, the D.C. Circuit applied this standard in the
context of a federal tax case, where the government also
sought production of work product that the taxpayer
company, Dow, had disclosed to its independent auditor,
Deloitte. 610 F.3d at 133. There, the government argued
that Dow’s disclosure of its attorney work product to
Deloitte waived the protection because Deloitte was either a
potential adversary or a conduit to an adversary. Id. at 140–
41. In rejecting both arguments, the D.C. Circuit provided
some useful guidance on how to determine whether
disclosure to an adversary, or a conduit to an adversary, has
occurred.


potential adversaries to obtain the information.’” (citation and quotation
omitted)).
24          UNITED STATES V. SANMINA CORP.

    Addressing whether Deloitte was a “potential adversary”
to Dow, the D.C. Circuit framed the relevant question as “not
whether Deloitte could be Dow’s adversary in any
conceivable future litigation, but whether Deloitte could be
Dow’s adversary in the sort of litigation the [work-product
documents] address.” Id. at 140. In concluding “that the
answer must be no,” the court noted that, in preparing the
work product, “Dow anticipated a dispute with the IRS, not
a dispute with Deloitte,” and the work product concerned tax
implications that “would not likely be relevant in any dispute
Dow might have with Deloitte.” Id.

     As to the “conduit to an adversary” analysis, the D.C.
Circuit noted that its prior applications of the “maintenance
of secrecy” standard have generally involved “two discrete
inquiries in assessing whether disclosure constitutes
waiver.” Id. at 141. The first inquiry is “whether the
disclosing party has engaged in self-interested selective
disclosure by revealing its work product to some adversaries
but not to others.” Id. If so, “[s]uch conduct militates in
favor of waiver” based on fairness concerns. Id. The second
inquiry is “whether the disclosing party had a reasonable
basis for believing that the recipient would keep the
disclosed material confidential.” Id. This “reasonable
expectation of confidentiality” could “derive from common
litigation interests between the disclosing party and the
recipient,” or it “may be rooted in a confidentiality
agreement or similar arrangement between the disclosing
party and the recipient.” Id.

    These points of inquiry into the disclosing party’s
“selective disclosure” and “reasonable expectation of
confidentiality”—while highly relevant and often
dispositive—are not the only considerations at play in
assessing whether a work-product disclosure is inconsistent
            UNITED STATES V. SANMINA CORP.                 25

with the maintenance of secrecy against adversaries. Rather,
the fact-intensive analysis requires a consideration of the
totality of the circumstances and is ultimately guided by the
same principle of fundamental fairness that underlies much
of our common law doctrine on waiver by implication.
Thus, we may find the work-product immunity waived
where the disclosing party’s conduct has reached a “certain
point of disclosure” towards his adversary such that “fairness
requires that his privilege shall cease, whether he intended
that result or not.” Weil, 647 F.2d at 24. Under the fairness
doctrine however, a court must be careful to “impose a
waiver no broader than needed to ensure the fairness of the
proceedings before it. Because a waiver is required so as to
be fair to the opposing side, the rationale only supports a
waiver broad enough to serve that purpose.” Bittaker,
331 F.3d at 720.

    In light of these relevant guideposts, we turn to whether
Sanmina voluntarily disclosed the Attorney Memos “to an
adversary or a conduit to an adversary” either when it
disclosed the Attorney Memos to DLA Piper or when it
provided the DLA Piper Report to the IRS.

                             B.

    The question of whether Sanmina’s disclosure of the
Attorney Memos to DLA Piper alone qualifies as a
“disclosure to an adversary” is fairly easy to answer. We
conclude it does not. The government readily concedes that
DLA Piper was not an adversary to Sanmina. Nor was DLA
Piper a potential adversary. As Deloitte and other courts
have held, a taxpayer’s disclosure of its attorney work
product to an independent auditor does not constitute
disclosure to an adversary sufficient to waive the protection.
See Deloitte, 610 F.3d at 139 (“Among the district courts that
have addressed this issue, most have found no waiver.”)
26          UNITED STATES V. SANMINA CORP.

(citing cases). In that same vein, Sanmina’s disclosure of the
Attorney Memos to DLA Piper for the purpose of obtaining
a valuation analysis may render DLA Piper a third party
insofar as attorney-client privilege is concerned, but it does
not transform DLA Piper into an adversary or even a
potential adversary with respect to the memoranda. Similar
to the work product at issue in Deloitte, the Attorney Memos
were prepared in anticipation of a dispute between Sanmina
and the IRS, not between Sanmina and DLA Piper, and they
involve legal assessments of potential tax implications for
Sanmina, which would likely be irrelevant in any potential
dispute between Sanmina and DLA Piper. Id. at 140.

    The government argues that DLA Piper was nonetheless
a “conduit to an adversary” because the DLA Piper Report
“was intended for disclosure to interested tax authorities”
and any “expectation of confidentiality was therefore
absent.” The relevant inquiry, however, is not whether
Sanmina expected confidentiality over the DLA Piper
Report. It is whether Sanmina “had a reasonable basis for
believing that [DLA Piper] would keep the [Attorney
Memos] confidential” in the process of producing its
valuation analysis. Deloitte, 610 F.3d at 141. That Sanmina
shared the Attorney Memos with DLA Piper to obtain a
valuation report for the IRS does not necessarily mean that
Sanmina knew or should have known that the resulting DLA
Piper Report would disclose or make reference to its attorney
work product. If anything, Sanmina’s enlistment of DLA
Piper’s assistance in anticipation of litigation with the IRS
indicates a “common litigation interest” between Sanmina
and DLA Piper insofar as the Attorney Memos are
concerned. Id. at 142. Furthermore, as discussed earlier,
some facts in the record support a reasonable belief on
Sanmina’s part that the Attorney Memos were maintained
within a confidential relationship with DLA Piper. See
            UNITED STATES V. SANMINA CORP.                 27

supra note 3. On balance, the circumstances suggest that
Sanmina had a reasonable expectation of confidentiality
over the Attorney Memos at the time of their disclosure to
DLA Piper.

     There is also no indication that Sanmina was engaging in
“self-interested selective disclosure” when it provided the
memoranda to DLA Piper. Id. at 141. “Selective disclosure
involves disclosing work product to at least one adversary.”
Id. at 142. As we have already found and the government
concedes, DLA Piper was not an adversary to Sanmina when
it received the Attorney Memos, nor were any of the other
entities in receipt of the memoranda. Accordingly, we
conclude that Sanmina’s disclosure of the Attorney Memos
to DLA Piper did not constitute a disclosure to an adversary
or a conduit to an adversary sufficient to waive the work-
product privilege.

                             C.

    Although Sanmina’s disclosure of the Attorney Memos
to DLA Piper in itself did not waive work-product
protection, the more difficult question is whether Sanmina
waived such protection when it provided the IRS with the
DLA Piper Report. Under the “disclosure to an adversary”
standard, there is no dispute that the IRS is an adversary to
Sanmina insofar as the Attorney Memos are concerned.
However, Sanmina did not disclose the actual Attorney
Memos to the IRS; rather, it disclosed a valuation report that
cited to the protected memoranda. Sanmina argues that
because the DLA Piper Report did “not disclose or describe
the contents of the Attorney Memos,” there is no
“disclosure” sufficient to waive the memoranda’s work-
product protection.
28             UNITED STATES V. SANMINA CORP.

     The concept that waiver by disclosure requires the
disclosure of some “content” of a privileged document—or
at least more than the fact of its existence—makes intuitive
sense. It also finds support from case law. 9 This point,
however, is not wholly dispositive to our waiver analysis.
As we have recognized in the attorney-client privilege
context, there is a difference between express and implied
waivers. This framework is also applicable in the context of
work-product protection, where an express waiver generally
occurs by disclosure to an adversary, while an implied
waiver occurs by disclosure or conduct that is inconsistent
with the maintenance of secrecy against an adversary. See
In re Martin Marietta Corp., 856 F.2d 619, 625–26 (4th Cir.
1988) (finding a regulatory disclosure of work product
“impliedly waived the work product privilege as to all non-
opinion work product on the same subject matter as that
disclosed” but not to opinion work product). Sanmina’s
claim that the DLA Piper Report does not disclose any of the
content of the Attorney Memos to the IRS may foreclose a
finding of express waiver in this case, but it is only one factor



     9
      “The case law is well settled that disclosing the fact that there were
confidential communications between a client and his or her attorney—
or even disclosing that certain subjects confidentially were discussed
between a client and his or her attorney—does not constitute a waiver by
partial disclosure.” Roberts v. Legacy Meridian Park Hosp., Inc., 97 F.
Supp. 3d 1245, 1253 (D. Or. 2015). “The disclosure must be of
confidential portions of the privileged communications. This does not
include the fact of the communication, the identity of the attorney, the
subject discussed, and details of the meetings, which are not protected
by the privilege.” Id. (citing 2 Paul R. Rice, Attorney-Client Privilege in
the United States § 9:30 at 153–56 (2014)). This proposition also finds
inferential support from the statement in Weil that “voluntary disclosure
of the content of a privileged attorney communication” constitutes
subject matter waiver. 647 F.2d at 24 (emphasis added).
            UNITED STATES V. SANMINA CORP.                29

we consider in determining whether to find an implied
waiver.

    Thus, the focal point of our waiver inquiry is whether,
under the totality of the circumstances, Sanmina acted in
such a way that is inconsistent with the maintenance of
secrecy against its adversary in regard to the Attorney
Memos. More broadly, we must ask whether and to what
extent fairness mandates the disclosure of the Attorney
Memos in this case. While we are generally guided by the
same fairness principle underlying waivers by implication in
the attorney-client privilege context, the overriding concern
in the work-product context is not the confidentiality of a
communication, but the protection of the adversary process.

    Here, Sanmina obtained a valuation report from DLA
Piper in anticipation of scrutiny from the IRS over a claimed
tax deduction. When asked for proof from the IRS, Sanmina
responded with the DLA Piper Report—a document that
expressly referred to the Attorney Memos. Presumably,
Sanmina could have chosen to substantiate the deduction
with other documents that did not make reference to the
Attorney Memos but did not. Such conduct seems
inconsistent with Sanmina’s purported goal of keeping the
memoranda secret from the IRS. Assuming that Sanmina
reasonably expected confidentiality over the Attorney
Memos when sharing them with DLA Piper, this expectation
became far less reasonable once Sanmina decided to disclose
to the IRS a valuation report that explicitly cited the
memoranda as a basis for its conclusions. In doing so,
Sanmina increased the possibility that the IRS, its adversary
in this matter, might obtain its protected work product, and
thereby engaged in conduct inconsistent with the purposes
of the privilege.
30          UNITED STATES V. SANMINA CORP.

    To the extent that Sanmina implicitly waived the work-
product privilege, the scope of its waiver must be “closely
tailored . . . to the needs of the opposing party” and limited
to what is necessary to rectify any unfair advantage gained
by Sanmina from its conduct. Bittaker, 331 F.3d at 720. In
that regard, it is not clear what unfair advantage Sanmina has
gained from its conduct, or how the IRS has been unfairly
disadvantaged, particularly at the current stage of
proceedings. The dispute before us is whether to enforce a
petition for a summons in a tax audit initiated by the IRS.
The parties have not yet engaged in any formal litigation
regarding the underlying validity of Sanmina’s claimed tax
deduction. Even if Sanmina may have temporarily reaped
the benefit of its claimed tax deduction, the potential
consequences of Sanmina’s decision to withhold the
Attorney Memos and support the deduction with a
questionable valuation report ultimately bear more heavily
on Sanmina than on the IRS. We disagree with the district
court’s conclusion that, without the disclosure of the
Attorney Memos, “the IRS or any other reader would be
forced to simply accept the [DLA Piper] opinion without
access to the foundational material.” At this audit stage, the
IRS is not required to accept the conclusions in the DLA
Piper Report at all. Even without access to the Attorney
Memos, the IRS could still proceed with its examination of
Sanmina’s returns, conclude that Sanmina has failed to
adequately support its claimed deduction with the DLA
Piper Report and other documents provided, and disallow
the deduction. See Interstate Transit Lines v. Comm’r of
Internal Revenue, 319 U.S. 590, 593 (1943) (stating “the
now familiar rule that an income tax deduction is a matter of
legislative grace and that the burden of clearly showing the
right to the claimed deduction is on the taxpayer”). So long
as Sanmina continues to refuse to produce the Attorney
            UNITED STATES V. SANMINA CORP.                 31

Memos, it faces the likely risk of an unfavorable decision
from the IRS in regard to its tax deduction.

    The Attorney Memos, as described by Sanmina’s in-
house counsel and confirmed by the district court’s review,
contain both factual discussions of the relevant transactions
and legal analyses of these facts in light of various tax law
authorities. Thus, the memoranda contain both factual work
product and opinion work product. Based on Sanmina’s
overall conduct, Sanmina has implicitly waived protection
over any factual or non-opinion work product in the
Attorney Memos that serve as foundational material for the
DLA Piper Report. However, the IRS provides no reason
why the scope of this implied waiver should encompass the
opinion work product contained in the Attorney Memos.
Besides its general argument the Attorney Memos are
needed to understand the DLA Piper Report, the IRS does
not explain why the “mental impressions, conclusions,
opinions or legal theories” of Sanmina’s in-house attorneys
are specifically at issue or critical to its assessment of the
deduction’s legal validity. Hickman v. Taylor, 329 U.S. 495,
508 (1947). We have held that such opinion work product
is discoverable only “when mental impressions are at issue
in a case and the need for the material is compelling.”
Holmgren v. State Farm Mut. Auto. Ins. Co., 976 F.2d 573,
577 (9th Cir. 1992); see also Upjohn Co. v. United States,
449 U.S. 383, 401 (1981) (“[S]uch work product cannot be
disclosed simply on a showing of substantial need and
inability to obtain the equivalent without undue hardship.”).

    According to Sanmina, it has produced to the IRS both
the DLA Piper Report as well as the underlying transactional
documents on which the Attorney Memos and the DLA
Piper Report relied. These disclosures, along with our
ordered disclosure of the factual work product contained in
32           UNITED STATES V. SANMINA CORP.

the Attorney Memos, should provide the IRS with the same
underlying facts and data on which Sanmina’s attorneys
relied in generating the legal opinions contained in the
Attorney Memos. With this information, the IRS should be
able to rely on its own attorneys to analyze the relevant facts
in light of the applicable tax authorities to determine the
legal validity of Sanmina’s tax deduction. While it might
certainly be helpful to the IRS to have access to the entirety
of the memoranda, this reason does not justify the IRS’s
entitlement to the legal theories and opinions of its potential
adversary in litigation. In fact, mandating full disclosure of
such protected work product under these circumstances may
potentially undermine the adversary process by allowing the
IRS the opportunity to litigate “on wits borrowed from the
adversary” in a future legal dispute with Sanmina. Hickman,
329 U.S. at 516 (Jackson, J., concurring).

    We conclude that fairness does not require the
categorical disclosure of Sanmina’s protected work product
to the IRS at this stage of prelitigation. Rather, fairness
requires, at most, the disclosure of the factual, or non-
opinion, work product contained in the Attorney Memos
upon which the DLA Piper Report relies. Any opinion work
product—meaning, the attorney’s “mental impressions,
conclusions, opinions or legal theories”—contained in the
Attorney Memos shall remain protected by the work-product
doctrine.

                              V.

    Sanmina waived the attorney-client privilege when it
disclosed the Attorney Memos to DLA Piper. However,
such disclosure did not automatically waive work-product
protection over the Attorney Memos. Rather, waiver of
work-product immunity requires either disclosure to an
adversary or conduct that is inconsistent with the
            UNITED STATES V. SANMINA CORP.                33

maintenance of secrecy against its adversary. Under this
standard, Sanmina did not expressly waive work-product
immunity merely by providing the Attorney Memos to DLA
Piper, but its subsequent use of the DLA Piper Report to
support its tax deduction in an audit by the IRS was
inconsistent with the maintenance of secrecy against its
adversary. In imposing an implied waiver of the work-
product privilege in this case, we conclude that the fairness
principle does not require the categorical disclosure of the
Attorney Memos at this stage. Rather, Sanmina’s implied
waiver of the work-product protection only extends to the
factual portions of the Attorney Memos.

    Thus, we GRANT IN PART and DENY IN PART the
IRS’s petition to enforce its summons. We order disclosure
of only the factual content of the Attorney Memos on which
the DLA Piper Report relies. We remand to the district court
for the limited purpose of determining the specific portions
of the Attorney Memos that should be disclosed to the IRS
and ordering disclosure consistent with this opinion.
