On January 20, 2017, President Trump's Chief of Staff Reince Priebus issued a memorandum to the heads of the executive departments and agencies calling for a regulatory freeze pending review – a practice that is relatively routine for new incoming presidential administrations. Specifically, the memorandum prohibits agencies from sending any regulation to the Office of Federal Register (OFR) prior to review and approval; requires agencies to immediately withdraw unpublished regulations for review and approval; and mandates that agencies temporarily postpone the implementation of published, but not yet effective, regulations for 60 days. Regulations subject to statutory or judicial deadlines are excluded from the aforementioned actions, but agencies must timely identify them to the OMB Director. Agencies also may identify regulations they believe should not be subject to the aforementioned procedures, namely those affecting "critical health, safety, financial, or national security matters, or for some other reason."