Opinion for the Court filed by Circuit Judge WILLIAMS.
This case presents issues concerning the scope and application of the attorney work product privilege under the Freedom of Information Act (“FOIA”), 5 U.S.C. § 552 (1982 & Supp. III 1985).
The Internal Revenue Service (“IRS”) has adopted a system of statistical sampling to audit large accounts. From the audit of a portion of the items in an account balance or in a class of transactions, the IRS infers conclusions as to the entire *126 balance or class. Before adopting the program, it had its attorneys prepare two memoranda analyzing the legal ramifications of the system. Relying at least partially on these memoranda, it concluded that statistical sampling presented an acceptable legal risk and authorized the program. The IRS made the decision public in § 42(18)1 of its Internal Revenue Audit Manual, stating: “The Office of the Chief Counsel and the Department of Justice have jointly analyzed the legal ramifications of [the statistical sampling program] and have concluded that substantial authority exists for [such program].”
Plaintiff, a law firm with an active tax practice, filed a FOIA request for production of all memoranda and supporting documents relating to the government’s legal analysis of the program. The IRS responded by declaring all of the requested materials privileged from disclosure under 5 U.S.C. § 552(b). Plaintiff filed an administrative appeal contesting the claim of privilege, and, after the IRS failed to act on the appeal for four months, initiated this action in the District Court.
While plaintiff’s motion for summary judgment was pending, the IRS produced sanitized versions of the two memoranda. 1 In its letter to plaintiff releasing these documents, the IRS expressly waived any claim of attorney-client or deliberative process privilege, but asserted the attorney work product privilege with respect to the excisions. 2 Plaintiff pressed for disclosure of the withheld material, but the District Court entered summary judgment in favor of the IRS.
Plaintiff now asserts that the District Court (1) erred in regarding the excisions as attorney work product and (2) lacked the information minimally necessary to evaluate the IRS’s claim of privilege.
I. Work Product: the Requirement of Preparation in Anticipation of Litigation
FOIA excepts from the general rule of disclosure memoranda “which would not be available by law to a party ... in litigation with the agency.” 5 U.S.C. § 552(b)(5) (1982). This exemption encompasses the attorney work-product rule.
Federal Trade Commission v. Grolier, Inc.,
The work product privilege enables a lawyer to develop his mental impressions and legal theories without fear of having his adversaries rummage through them at leisure. See
Hickman v. Taylor,
Though not seriously contesting the proposition that the memoranda in question were prepared in anticipation of litigation in the normal sense of the phrase, plaintiff rests its case on our observation in
Coastal States
that this prerequisite is not met unless the agency established “that a spe
*127
cific claim had arisen, was disputed ..., and was being discussed in the memorandum.”
The court in
Coastal States
identified the function of the documents as the critical issue.
Id.
at 858 (citing
National Labor Relations Board v. Sears, Roebuck & Co.,
The court rejected the agency’s contention that any document prepared by an attorney in the context of an audit was automatically privileged from disclosure as work product. In drawing a line between the two classes of documents at issue, it regarded as pivotal the question whether a specific claim had arisen. The memoranda containing mere “neutral, objective analyses of agency regulations” could not meet the test, but the more pointed documents might. (The court held that the agency failed to provide adequate data to meaningfully evaluate its claims as to the latter documents.)
The documents withheld by the IRS here serve a function quite different from those involved in
Coastal States.
There the documents were like an agency manual, fleshing out the meaning of the statute it was authorized to enforce. Here the IRS memos advise the agency of the types of legal challenges likely to be mounted against a proposed program, potential defenses available to the agency, and the likely outcome. Similarly, plaintiff here is not trying to ascertain the agency’s view of the law in order to comply or to advise clients on how to comply; it is seeking the agency’s attorneys’ assessment of the program’s legal vulnerabilities in order to make sure it does not miss anything in crafting its legal case against the program.
3
This is precisely the type of discovery the Court refused to permit in
Hickman v. Taylor,
Thus in
Coastal States
the “specific claim” requirement served to isolate those documents worthy of protection as attorney work product. Application of that requirement here would ignore the function performed by the withheld material,
see Coastal States,
II. The District Court’s Process in Evaluating the Exemption Claim
Plaintiff asserts that the District Court lacked the materials minimally necessary to properly evaluate the IRS’s claim of privilege.
4
In FOIA cases the unresponsive agency bears the burden of proving that withheld material is privileged.
Coastal States,
The materials provided by the agency may take any form so long as they give the reviewing court a reasonable basis to evaluate the claim of privilege.
See Mead Data Central, Inc. v. United States Department of the Air Force,
Here the IRS provided the District Court with copies of the edited memoranda and a “Vaughn Index.” The trial judge reviewed the edited memoranda and concluded, as do we, that even their surviving portions constitute attorney work product. It was thus a fair inference that the edited portions also qualified as work product. At least it would be startling for the agency to release qualifying parts of a document and withhold less qualifying portions. The trial judge accordingly upheld the claim of privilege with respect to the excisions without evaluating the IRS’s Vaughn Index or ordering an in camera inspection of the material withheld. On the facts of this case, the District Court’s procedure was entirely suitable. 5
The decision below is
Affirmed.
Notes
. The excised material amounted to approximately two pages.
. Plaintiff suggests that the reference to the memoranda in the Audit Manual’s statement necessarily took them out from Exemption 5. Appellant’s Brief at 3, citing
National Labor Relations Board v. Sears, Roebuck & Co.,
. So far as we can tell plaintiff has yet to mount such an attack, but it is undisputed that plaintiff desires the withheld information for use in its representation of clients subject to the statistical sampling program.
. Plaintiff further asserts that because the IRS admitted to destroying documents that may have been responsive to its FOIA request, it has experienced hardship justifying disclosure of the privileged excisions.
See Hickman v. Taylor,
. Because we conclude that the sanitized memoranda themselves provided the trial judge with an adequate basis to evaluate the IRS’s claim of privilege, we need not consider the adequacy of the IRS’s Vaughn Index.
