What is a Vaughn index and when does the court make the agency produce one in FOIA litigation?

What a Vaughn Index Is

A Vaughn index is a detailed, itemized justification an agency files in court to defend the records or portions of records it withheld under a Freedom of Information Act (FOIA) request. The name comes from the 1973 federal appeals court decision Vaughn v. Rosen.

Because the requester cannot see the withheld material, a court cannot easily test whether a withholding was proper. The Vaughn index solves that problem by forcing the agency to describe, document by document, what it withheld and why. A typical entry identifies:

• the document (date, type, author/recipient, page count);
• a description specific enough to evaluate the claim, without revealing the protected content;
• the exact FOIA exemption(s) invoked; and
• an explanation of how that exemption applies to that record.

The goal is to give the requester and the judge enough information to challenge and review each withholding, rather than accepting a blanket “it’s exempt.”

When a Court Orders One

A Vaughn index is a litigation tool, not part of the ordinary administrative request. When you first submit a FOIA request, the agency generally has 20 business days to respond, and it explains withholdings through the exemptions it cites and the administrative appeal process. No index is required at that stage.

The index comes into play only after a requester sues in federal district court and the parties dispute whether withholdings were lawful. There is no automatic right to one. The court decides, often on motion, whether to require an index, when it is due, and how granular it must be. Judges may also accept agency declarations or review documents privately (in camera) instead of, or alongside, an index.

A few practical points:

• The agency, not the requester, bears the burden of justifying withholdings.
• An index that is too vague (“conclusory”) can be rejected, prompting a more detailed filing.
• Exemptions and procedures here are federal. State public-records laws vary, and many use different mechanisms.

For background on federal FOIA exemptions, appeals, and the request process, see /topics/foia-public-records/.