This bill amends the World Trade Center Health Program to expand access to mental health services and secure long-term funding for 9/11 responders and survivors. It allows licensed mental health providers, not just physicians, to conduct mental health evaluations and make certifications for program participants, with the program administrator issuing detailed regulations within 180 days. The bill also streamlines credentialing requirements for healthcare providers and clarifies that deceased individuals should not be counted in enrollment numbers. For funding, it appropriates $2.97 billion to the program's Special Fund for fiscal year 2024 and restructures how money flows between separate accounts, consolidating remaining balances into the main World Trade Center Health Program Fund through fiscal year 2090. The bill extends the timeline for adding new health conditions to the list from 90 to 180 days and funds these changes by adjusting Medicare payment timing rules, with any budget savings beyond what the bill costs going to the Medicare Improvement Fund.