This bill, known as the Modern, Clean, and Safe Trucks Act of 2026, proposes to repeal the 12-percent Federal retail excise tax currently imposed on new heavy trucks, tractors, and trailers. This excise tax is identified as the highest percentage rate of any federal ad valorem excise tax and significantly increases the upfront cost of these vehicles. For instance, it can add over $7,000 to new trailers, more than $20,000 to clean diesel trucks, and up to $50,000 for trucks with advanced engine technologies. The primary goal of this repeal is to incentivize the replacement of older, less efficient vehicles with modern, cleaner, and safer models. Congress finds that the existing tax discourages the adoption of new technologies, including electric and alternative-fueled trucks, which are crucial for reducing carbon emissions and accelerating the transition to zero-emission vehicles. By eliminating this financial barrier, the bill aims to advance the deployment of vehicles equipped with the latest environmental and safety advancements, thereby improving air quality and road safety. The legislation achieves this by striking Subchapter C of Chapter 31 from the Internal Revenue Code of 1986 and making several conforming amendments to related sections. While acknowledging that the excise tax currently contributes to the Highway Trust Fund, the bill suggests that Congress should consider a more reliable and consistent revenue mechanism for its funding. The repeal would apply to sales and installations occurring on or after the bill's enactment date.