Importance In 2018, the US Congress gave Medicare Advantage (MA) historic flexibility to address members’ social needs with a set of Special Supplemental Benefits for the Chronically Ill (SSBCIs). In response, the Centers for Medicare &amp;amp;amp; Medicaid Services expanded the definition of primarily health-related benefits (PHRBs) to include nonmedical services in 2019. Uptake has been modest; MA plans cited a lack of evidence as a limiting factor. Objective To evaluate the association between adopting the expanded supplemental benefits designed to address MA enrollees’ nonmedical and social needs and enrollees’ plan ratings. Design, Setting, and Participants This cohort study compared the plan ratings of MA enrollees in plans that adopted an expanded PHRB, SSBCI, or both using difference-in-differences estimators with MA Consumer Assessment of Health Care Providers and Systems survey data from March to June 2017, 2018, 2019, and 2021 linked to Medicare administrative claims and publicly available benefits and enrollment data. Data analysis was performed between April 2023 and March 2024. Exposure Enrollees in MA plans that adopted a PHRB and/or SSBCI in 2021. Main Outcomes and Measures Enrollee plan rating on a 0- to 10-point scale, with 0 indicating the worst health plan possible and 10 indicating the best health plan possible. Results The study sample included 388 356 responses representing 467 MA contracts and 2558 plans in 2021. Within the weighted population of responders, the mean (SD) age was 74.6 (8.7) years, 57.2% were female, 8.9% were fully Medicare-Medicaid dual eligible, 74.6% had at least 1 chronic medical condition, 13.7% had not graduated high school, 9.7% were helped by a proxy, 45.1% reported fair or poor physical health, and 15.6% were entitled to Medicare due to disability. Adopting both a new PHRB and SSBCI benefit in 2021 was associated with an increase of 0.22 out of 10 points (95% CI, 0.4-4.0 points) in mean enrollee plan ratings. There was no association between adoption of only a PHRB (adjusted difference, −0.12 points; 95% CI, −0.26 to 0.02 points) or SSBCI (adjusted difference, 0.09 points; 95% CI, −0.03 to 0.21 points) and plan rating. Conclusions and Relevance Medicare Advantage plans that adopted both benefits saw modest increases in mean enrollee plan ratings. This evidence suggests that more investments in supplemental benefits were associated with improved plan experiences, which could contribute to improved plan quality ratings.

New Supplemental Benefits and Plan Ratings Among Medicare Advantage Enrollees