How about an institution with policies establishing LOWER per diem rates than federal?  Would it be ok to write it up in a proposal as "federally approved per diem rates will be used" (or something to that effect)?

======================================================================
 Instructions on how to use the RESADM-L Mailing List, including
 subscription information and a web-searchable archive, are available
 via our web site at http://www.healthresearch.org (click on the
 "LISTSERV" link in the upper right corner)

 A link directly to helpful tips:  http://tinyurl.com/resadm-l-help
======================================================================