H.R. 9618, the DEF Act, cleared a committee markup on July 14, 2026.
H.R. 9618 — DEF Act
What it does
This bill freezes diesel engine emission standards for 10 years, preventing the EPA from adopting stricter pollution rules than those set in 2007–2010. It creates a legal safe harbor for diesel exhaust fluid (DEF) monitoring practices and engine modifications described in three specific EPA guidance documents issued in 2025–2026. After the 10-year freeze, any new standards must allow 5 years lead time and must weigh industry costs, operational disruption, and resale value alongside public health.
Quorum's transparency scan gave DEF Act a high transparency warning.
What happens next
H.R. 9618 cleared a committee markup. Next step: the committee votes to report it out.
Who is behind it
Filed by Julie Fedorchak. Cosponsored by Brad Finstad, Donald Davis, H. Griffith and Jack Bergman.