HUD) released Mortgagee Letter 2026-04, which updates environmental requirements within the Multifamily Accelerated Processing (MAP) Guide. The changes eliminate or revise several existing standards, including the removal of railroad vibration review requirements, updated setback rules for pressurized pipelines and high-voltage transmission lines, and new guidance defining noise-sensitive outdoor uses. These revisions are intended to simplify environmental review and clarify underwriting expectations.