Does Medicaid Expansion Lead to Income Adjustment? Evidence from the Survey of Income Program Participation
Mingjian Li
公開日: 2025/6/15
Abstract
Using monthly Survey of Income Program Participation (SIPP) data and a regression discontinuity (RD) design at the 138 percent Federal Poverty Line (FPL) threshold, this paper shows that childless adults in Medicaid expansion states lowered their lowest monthly earnings by about 39 FPL percentage points, equal to 700 dollars in 2025 for a two person household, to qualify for Medicaid. The response was largest when the individual mandate penalty was in effect and declined after the penalty was reduced to zero in 2019. Evidence from zero earnings months and hours worked indicates adjustments along both extensive and intensive margins. These results validate lowest monthly earnings as a practical eligibility measure and provide new evidence of substantial labor supply responses to the Affordable Care Act Medicaid notch.