US HB517

Amends Internal Revenue Code Section 7508A to allow the Treasury Secretary to postpone federal tax deadlines for state-declared disasters, not just federally-declared ones, upon written request from a state Governor or DC Mayor

Defines "qualified State declared disaster" to include natural catastrophes (hurricanes, tornadoes, earthquakes, tsunamis, volcanic eruptions, landslides, snowstorms, droughts) and fires, floods, or explosions regardless of cause

Extends mandatory tax deadline extensions from 60 days to 120 days for affected taxpayers in disaster areas

Applies to U.S. states plus District of Columbia, Puerto Rico, Virgin Islands, Guam, American Samoa, and Northern Mariana Islands

Takes effect for disaster declarations made after the date of enactment