Besides withholding any portion of a record, are there other reasons for not releasing records?

Yes, HHS may not release a record under the following circumstances:

1.  A reasonable search for requested information failed to identify/locate responsive records.
2.  The request is transferred to another Federal Agency to identify/locate responsive records.
3.  The request is withdrawn by the requester.
4.  The requester is unwilling to pay fees associated with a request, is past due in the payment of fees from a previous FOIA request, or disagrees with the fee estimate.
5.  A record has not been described with sufficient specificity to enable HHS personnel or contractors to locate it by conducting a reasonable search.
6.  The information requested is not a record within the meaning of the FOIA or HHS regulation.
7.  The request is a duplicate request; i.e., the requester asks for the same information more than once. This includes identical requests received via different means; e.g., electronic mail, facsimile, mail, and/or courier, at the same or different times. HHS will act only on the initial request.