Requires the Postal Service to send any proposal for a major, nationwide, or district-level change to postal services to the Postal Regulatory Commission (PRC) for an advisory opinion before spending money or taking steps to implement the change. The PRC must issue its advisory opinion within 180 days; the Postal Service may not implement or allot funds for the change until the opinion is issued, and the PRC can suspend changes that proceeded without the required review. The bill also makes the congressional disapproval process under Title 5, chapter 8 applicable to these proposals with two tailored definitions.