The transition to zero-emission transit buses in the U.S. is steadily progressing despite challenges like supply chain issues. CALSTART's 2025 report showcases the growth in ZEB adoption, with full-size ZEBs reaching 7,028 in July 2024, marking a 14% increase from the previous year. Battery-electric buses remain dominant, while fuel cell electric buses are also on the rise. Small ZEBs are gaining traction across public transit, private fleets, and university fleets. The Federal Transit Administration's funding in 2024 supported the addition of nearly 600 new ZEBs and infrastructure projects. States like California, New York, and Florida are leading in full-size ZEB adoption, with programs like HVIP and Truck Voucher Incentive Program stimulating ZEB uptake. The industry's commitment to cleaner transportation is highlighted by the positive growth and resilience of ZEB deployments, emphasizing the importance of federal and state support for a sustainable future.