What is the difference between a Glomar response and a regular FOIA denial?

A regular Freedom of Information Act (FOIA) denial and a “Glomar” response both result in the requester receiving no records, but they differ in a crucial way: what the agency is willing to acknowledge.

A regular FOIA denial

In a typical denial, the agency confirms that responsive records exist (or once existed) but withholds them, in whole or in part, under one or more of FOIA’s exemptions. The denial letter generally:

• Acknowledges the records exist
• Cites the specific exemption(s) being applied
• Withholds or redacts the protected material
• Explains appeal rights

Because the agency admits the records exist, the requester can challenge the withholding on the merits — administratively through an appeal, and ultimately in court.

A Glomar response

A Glomar response goes a step further. Instead of confirming and then withholding, the agency refuses to confirm or deny whether any responsive records exist at all. The name comes from a case involving a ship, the Glomar Explorer, where simply admitting that records existed would itself have revealed sensitive information.

Agencies use this approach when the very existence (or non-existence) of records is the protected fact. For example, confirming whether an agency holds records about a particular individual or activity could expose classified intelligence sources and methods, reveal an investigation, or invade personal privacy — harms that a normal “exists but exempt” answer would not prevent.

A Glomar response is still grounded in FOIA’s exemptions; the agency must tie its refusal to a specific exemption, just as it would in an ordinary denial. The difference is in the scope of what is being protected.

Why the distinction matters

• What is acknowledged: A regular denial confirms records exist; a Glomar neither confirms nor denies.
• What is protected: A denial protects the contents; a Glomar protects the fact of existence itself.
• Appeals: Both can be appealed, but a Glomar appeal often turns on whether existence can be acknowledged without causing the harm the exemption guards against.

For records and information-governance professionals, recognizing this difference helps in documenting responses accurately and in setting realistic expectations with requesters. You can explore related material on the FOIA and public records hub.