The Impact of the ACA Medicaid Fee Bump on Pediatricians’ Participation in Medicaid: Evidence from Massachusetts
Authors: Dass D. , Fung V. , Price M. 
Published: August 2020

Low fees have often been cited as a barrier to provider participation in Medicaid, which limits access to care for enrollees. Under the Affordable Care Act (ACA), Medicaid fees for primary care providers (PCPs) were raised temporarily to that of Medicare fee in 2013‐2014. The existing evidence on whether increasing fees improves the availability of providers is mixed and often relies on self‐reported information from providers. We used the natural experiment created by the ACA fee bump in Massachusetts to examine the impact of the ACA fee bump on pediatricians’ participation in Medicaid. Since Massachusetts expanded Medicaid prior to the ACA, this provides an opportunity to examine the impact of fee increases in a setting of stable coverage levels.We used data from the Massachusetts All Payer Claims Database (MA‐APCD) from 2010‐2013 to identify children (age of 1‐18 years) enrolled in Medicaid, and the National Plan and Provider Enumeration System (NPPES) data to identify Pediatricians using their primary taxonomy codes. We used two main measures of provider participation in Medicaid: (1) the percentage of pediatricians who had at least one outpatient Medicaid claim per year; and (2) among those with at least 1 claim, the number of Medicaid claims per pediatrician per year. In sensitivity analyses, we also examined higher thresholds for number of claims. We used logistic and linear regression models with provider‐level random effects to assess if there were changes in pediatrician participation in Medicaid during the first year of fee bump (2013) vs. the baseline period (2010‐2012), adjusting for providers’ 3‐digit ZIP codes.All Pediatricians (N = 4724) identified in the MA‐APCD provider file linked with NPPES data and children enrolled in Medicaid (N = 772 628).Mean costs per pediatric visit among Medicaid enrollees increased 25% from $89 to $111 (2010‐2012 vs. 2013). In 2010, 45.1% pediatricians in Massachusetts had at least one outpatient Medicaid claim; the mean number of Medicaid claims per pediatrician was 380(SD = 554). The percent of pediatricians with any Medicaid claim increased slightly to 47.3% in 2013, but there was no significant increase in participation associated with the first year of fee bump and participation in multivariate analyses (OR 1.03, 95% CI 0.91, 1.17 for 2013 vs. 2010‐2012). However, the number of outpatient claims per pediatrician per year who participated in Medicaid decreased by 14.3 (95% CI: −23.0, −5.7) in 2013 vs. 2010‐2012. Similar results were obtained from multivariate analyses using higher thresholds for number of claims.Fewer than half of pediatricians in Massachusetts provided outpatient care to Medicaid enrollees in 2010. Despite increases in primary care payments associated with the ACA, pediatricians’ participation in Massachusetts did not increase in the first year of the policy change.The effects of ACA fee bump could have been more muted in the first year given potential delays in implementation. The temporary nature of the policy change could have also limited its effects. Alternative approaches could be needed to increase the availability of providers for low‐income children.Agency for Healthcare Research and Quality.