More emitting bus projects won more funding than ever in FY 2025 in the Low or No Emission Buses program. 

The Low or No Emissions Bus Program, codified in 49 USC 5339(c), calls for the US Department of Transportation to award funds to the projects that reduce emissions the most compared to other buses.
As part of a concession made during the negotiations to pass the Infrastructure Investment and Jobs Act, the Low-No program received significantly more funding but also incorporated a 25% minimum set-aside for low emission buses. In FY 2022, the Biden administration awarded funds to 100% of applicants who applied for low emission buses (T4A Greener Fleets Report), but do to low demand, they were unable to hit the minimum and made up the difference in the following fiscal years.