Volume 56 | Number 3 | June 2021

Abstract List

Eric T. Roberts Ph.D., Sunita M. Desai PhD


To assess changes in physicians’ provision of care to duals (low‐income individuals with Medicare and Medicaid) in response to a policy that required Medicaid to fully pay Medicare's cost sharing for office visits with these patients. This policy—a provision of the Affordable Care Act—effectively increased payments for office visits with duals by 0%‐20%, depending on the state, in 2013 and 2014.

Data Sources

Fee‐for‐service claims for a 5% random sample of Medicare beneficiaries in 2010‐2016.

Study Design

We conducted a difference‐in‐differences analysis to compare changes in office visits among Qualified Medicare Beneficiaries (QMBs)—the largest subpopulation of duals for whom payment rates were affected by this policy—to changes among other low‐income Medicare beneficiaries for whom payment rates were unaffected (pooled across all states). Next, we conducted a triple‐differences analysis that compared changes between QMBs and other low‐income beneficiaries in 33 states with payment rate increases of approximately 20% to analogous changes in 14 states without payment increases.

Data Collection

The study included administrative Medicare enrollment and claims data for QMBs and a comparison group of other low‐income Medicare beneficiaries (1 914 073 beneficiary‐years from 2010 to 2016).

Principal Findings

Nationally, we did not find a differential increase in office visits among QMBs versus other low‐income beneficiaries that coincided with this payment change. In the triple‐differences analysis, we did not observe a greater increase in visits among QMBs vs other low‐income beneficiaries in states where the policy resulted in large (approximately 20%) increases in payment rates vs states where payment rates were unaffected (triple‐differences estimate: −0.12 annual visits, 95% CI: −0.28, 0.04;  = 0.15).


Physicians’ provision of care to low‐income Medicare beneficiaries may not be responsive to short‐run payment changes.