Importance: The Patient Protection and Affordable Care Act (ACA) temporarily increased primary care practitioners' (PCP) Medicaid fees to that of Medicare for 2013 to 2014 (fee bump) to help accommodate potential increases in demand for care with ACA coverage expansion. This also increased fees for PCPs treating dual-eligible Medicare and Medicaid beneficiaries in many states and eliminated payment differentials for dual-eligible vs non-dual-eligible Medicare beneficiaries that could limit access to care.
Objective: To examine the association between the ACA fee bump and primary care visits for dual-eligible Medicare and Medicaid beneficiaries.
Design, setting, and participants: This cohort study used a difference-in-difference design and Medicare claims data from 2012 to 2016 to compare changes in visit rates for full-subsidy dual-eligible Medicare and Medicaid beneficiaries vs non-dual-eligible Medicare beneficiaries with low income whose fees did not change. Changes were examined overall and separately in states with temporary, extended, or minimal fee increases for dual-eligible vs non-dual-eligible beneficiaries in 2013 to 2014 (mandatory bump) and 2015 to 2016 (postbump or bump extension) vs 2012 (prebump). The study used linear regression models with beneficiary fixed effects, adjusting for time-changing area and beneficiary characteristics. Statistical analysis was performed from February 2018 to November 2019.
Exposure: ACA-mandated Medicaid fee bump.
Main outcomes and measures: Primary care visits per 100 beneficiaries overall and visits billed by physicians vs nurse practitioners and physician assistants.
Results: The study included 3 052 044 dual-eligible and non-dual-eligible beneficiaries in 2012; 1 516 534 (49.7%) were aged 65 years or younger, 1 797 556 (58.9%) were women, and 1 754 626 (57.5%) had non-Hispanic White race/ethnicity. Overall primary care visit rates for dual-eligible beneficiaries were unchanged or decreased slightly relative to non-dual-eligible beneficiaries during the fee bump (2013-2014) and the postbump or bump extension period (2015-2016) vs baseline. Compared with non-dual-eligible beneficiaries, visit rates with primary care physicians declined more uniformly for dual-eligible beneficiaries across state groups and time periods (difference-in-difference: -0.37 [95% CI, -0.43 to -0.32] visits per 100 beneficiaries in 2013-2014 vs 2012; P < .001; and difference-in-difference: -0.62 [95% CI, -0.68 to -0.56] visits per 100 beneficiaries in 2015-2016 vs 2012; P < .001), whereas visits with nurse practitioners and physician assistants increased over time (difference-in-difference: 0.11 [95% CI, 0.08 to 0.14] visits per 100 beneficiaries in 2013-2014 vs 2012; P < .001; and difference-in-difference: 0.46 [95% CI, 0.43 to 0.50] visits per 100 beneficiaries in 2015-2016 vs 2012; P < .001). These changes, however, were not associated with the timing of the payment changes.
Conclusions and relevance: The ACA fee bump was not associated with increases in primary care visits for dual-eligible Medicare and Medicaid beneficiaries. Visits for dual-eligible beneficiaries with primary care physicians decreased after the ACA, a decrease that was partially offset by increases in visits with nonphysician clinicians.