- Stage
- In committee
- Started in
- House
- Sponsors
- 8
- Latest action
- Jul 14, 2026
What it does
The Diesel Engine Flexibility Act (DEF Act) would amend the Clean Air Act to preserve regulatory stability for on-road and nonroad diesel vehicles and engines by prohibiting the EPA from implementing more stringent emission standards than the 2007/2010 on-road or Tier 4 nonroad standards for 10 years after enactment, while allowing certain flexibility measures like software updates and DEF quality monitoring if consistent with specified guidance documents. After the 10-year period, any new standards must apply for at least 3 model years and take effect no earlier than 5 years after promulgation, and the EPA must consider operational, economic, and harmonization impacts when setting future…
No official summary is available here. This one was written by AI from the bill’s text.
Where it stands
Introduced (Done)
Committee (Current step)
Floor (Not started)
Law (Not started)
What moved
Who is involved
Sponsors
The lawmakers who put their names on it, lead sponsors first.
Where it goes next
While a bill can still move, the questions are about people and money.