Here is what google ai says . . .Isn't OMB?
Yes, the Office of Management and Budget (OMB) is considered subject to the Administrative Procedure Act (APA) to a certain extent, meaning it must follow certain procedural requirements when issuing regulations, particularly regarding the review process of other agencies' rules which are subject to the APA; however, the OMB itself is not typically directly regulated by the APA in its own internal operations.