Health Center Service Expansion and Provider Shortage Reduction Act This bill provides funding through FY2028 for certain services under the Community Health Center Program, which supports outpatient health care facilities that provide comprehensive primary care to medically underserved populations. It also provides funding through FY2028 to expand the National Health Services Corps, which provides scholarships and student loan repayment awards to health care providers who agree to work in areas with health care provider shortages. In particular, the bill requires that health centers provide behavioral health, mental health, and substance use disorder services and provides funding for those services. (Currently, centers may provide those as additional services.) Furthermore, the bill provides funding for (1) expanding the operating hours of community health centers; and (2) New Access Point Grants, which assist centers to establish new delivery sites for care.