This legislation aims to significantly expand access to mental and behavioral health services for beneficiaries of Medicare, Medicaid, and the Children's Health Insurance Program (CHIP). It achieves this by permitting reimbursement for services provided by supervised psychology trainees, thereby addressing critical workforce shortages in mental health. The bill seeks to improve overall mental health care accessibility across these vital federal programs. For Medicare , the bill amends the Social Security Act to allow reimbursement for psychological services furnished by advanced psychology trainees , such as doctoral interns and postdoctoral residents, under the general supervision of a clinical psychologist. These trainees must be enrolled in accredited programs and meet specific experiential training requirements, with the services billed by the supervising psychologist who is not required to be physically present during the service. The Secretary of Health and Human Services must also develop a new "GC" modifier code within one year for accurate billing of these services. Regarding Medicaid and CHIP , the bill directs the Secretary of HHS to issue comprehensive guidance to states within one year on strategies to overcome existing barriers to covering services provided by advanced psychology trainees. This guidance will include recommendations for legal mechanisms, appropriate billing codes and modifiers, and examples of states that have successfully utilized waivers to enable such coverage.