When can an agency give a Glomar response and how do I challenge it?

A “Glomar response” is when an agency refuses to confirm or deny that responsive records even exist. Instead of producing, withholding, or denying records, the agency says it can “neither confirm nor deny” that any record is in its possession. The name comes from a 1970s case involving a vessel called the Glomar Explorer.

When a Glomar response is allowed

A Glomar response is the exception, not the norm. An agency may use it only when the very fact of whether a record exists is itself protected by a FOIA exemption. In other words, simply acknowledging that records do or do not exist would cause the harm the exemption is meant to prevent.

This most often arises with:

• National security and intelligence sources or methods, where confirming a record exists could reveal classified activity.
• Personal privacy, where confirming that the government holds records about a named individual (for example, whether someone is under investigation) would itself be an unwarranted invasion of privacy.
• Law enforcement, where acknowledging an investigation could tip off a target or harm the case.

The agency must still tie its Glomar response to a specific exemption and explain, at least in general terms, why confirming existence would cause harm. A blanket “we won’t say” without a legal basis is not proper.

How to challenge a Glomar response

You have the same appeal rights as with any other FOIA denial:

1. File an administrative appeal with the agency, usually within the deadline stated in its response letter. Argue that the agency has not justified the Glomar, that the existence of records is already public (“official acknowledgment”), or that the cited exemption does not apply.
2. Point to prior official acknowledgment. If an agency or official has already publicly confirmed the records or activity exist, a Glomar response is generally no longer available for that information.
3. Seek help from OGIS. The Office of Government Information Services offers free mediation and can review whether the agency followed the law.
4. Litigate in federal court if the appeal is denied. A court can require the agency to justify its Glomar.

Note that the federal FOIA generally gives agencies 20 business days to respond. State public-records laws have their own standards and timelines, which vary widely, so check your specific state’s law.