That is the question Park, Langellier, and Meyers (2022) aim to estimate in their recent Health Services Research publication. The authors use 2015-2017 data from the Centers for Medicare and Medicaid services and control for other differences between integrated and non-integrated Medicare Advantage (MA) plans using state fixed effects and contract random effects. Using this approach, they find:
Integrated MA plans were associated with $19.4 (95% CI: 9.2, 29.7) and $16.6 (95% CI: 10.3, 22.9) higher Part C and Part D monthly premiums, but were associated with higher star quality ratings…Integrated MA plans were associated with $40.5 (95% CI: -54.0, -26.9) lower non-claims costs than non-integrated MA plans. There was limited evidence that integrated MA plans provided more generous supplemental benefits than non-integrated MA plans. Enrollment rates in integrated MA plans were particularly low among socially marginalized groups [3.4 (95% CI: -5.9, -1.0), 4.7 (95% CI: -8.5, -0.9), and 4.4 (95% CI: -6.4, -2.4) percentage points lower among non-Hispanic Black, Medicare-Medicaid dual eligible, and the disabled].
Integrated MA plans may improve efficiency and quality, but these benefits accrue disproportionately to more socially advantaged Medicare beneficiaries due to enrollment trends.