I’ve written before about the importance of the Affordable Care Act’s Medicaid expansion and about the role of community health centers in delivering primary care to underserved patients. With roughly half of the states declining the now-optional Medicaid expansion and an uncertain federal funding environment, though, the extent to which health centers will be able to serve the newly insured is up in the air. A new report from the Geiger Gibson/RCHN Community Health Foundation Research Collaborative puts some numbers on the variability. Under different Medicaid expansion and funding scenarios, the number of patients community health centers can care for in 2020 could be as low as 20 million or as high as 37 million. (Disclosure: the Geiger Gibson Program is based at the George Washington University School of Public Health & Health Services, where I work.)

Community health centers — also known as federally qualified health centers, or FQHCs — provide comprehensive, high-quality primary care to all, regardless of insurance status. Nationally, 72% of health centers’ patients live at or below the federal poverty level; 36% are uninsured, and 39% have Medicaid or CHIP coverage. Community health centers are a natural source of primary care for new Medicaid enrollees and others gaining coverage under the ACA, so the law included substantial additional funding for health center expansion through 2015. In states that are expanding Medicaid eligibility to legal residents with incomes of up to 133% of the federal poverty level, health centers will also get additional revenue as more of their patients gain Medicaid coverage.

The report’s authors calculate health center capacity under “high” and “low” federal funding scenarios, and under two Medicaid expansion scenarios: one in which all states expand Medicaid, and one in which only the states that have already stated an intention to expand Medicaid do so. (The latter scenario involves 25 states and DC expanding Medicaid eligibility.) Here are their estimates of how many patients health centers will be able to serve in 2020 under different conditions:

• Low federal funding, limited Medicaid expansion: 20.1 million patients — a reduction from the 21.1 million health centers currently serve.
• High federal funding, limited Medicaid expansion: 35.6 million patients
• Low federal funding, full Medicaid expansion: 20.8 million patients
• High federal funding, full Medicaid expansion: 37 million patients

It’s interesting to see that even without additional states expanding Medicaid, higher levels of federal funding can still increase health center capacity substantially. What these numbers don’t show, however, is the potential for an ever-growing gap in healthcare access between states that do and don’t expand Medicaid.