20 CFR 402.195 - How a request is denied.
(a) Oral requests. If we cannot comply with your oral request because the Deputy Executive Director for the Office of Public Disclosure, Office of the General Counsel (or designee) has not previously made a determination to release the record you want, we will tell you that fact. If you still wish to pursue your request, you must put your request in writing.
(b) Written requests. If you make a written request and the information or record you requested will not be released, we will send you an official denial in writing. We will explain why the request was denied (for example, the reasons why the requested document is subject to one or more clearly described exemptions), will include the name and title or position of the person who made the decision, and what your appeal rights are.
(c) Unproductive searches. We make a diligent search for records to satisfy your request. Nevertheless, we may not be able always to find the records you want using the information you provided, or they may not exist. If we advise you that we have been unable to find the records despite a diligent search, this does not constitute a denial of your request.