Medicare Advantage customer service is used most by higher-need patients.

Objectives: To examine characteristics of Medicare Advantage (MA) enrollees who use their plan's customer service to help plans understand how to better meet members' needs.

Study Design: National sample of 259,533 respondents to MA Consumer Assessment of Healthcare Providers and Systems survey enrolled in any of the 559 MA contracts in 2022.

Methods: We assessed the association between self-reported customer service use in the prior 6 months and enrollee demographic, coverage, health, and health care utilization characteristics. We used weighted linear regression models to test for bivariate and multivariate associations between customer service use and enrollee characteristics.

Results: Forty-two percent of MA enrollees reported using customer service in the prior 6 months. Use was 20 percentage points (PP) higher for those in poor vs excellent/very good general health, 13 PP higher for those in poor vs excellent/very good mental health, and 14 PP higher for those reporting 3 or more vs no chronic conditions. Those using customer service more often had lower educational attainment, had limited income and assets, preferred another language to English, and had greater health care utilization.

Conclusions: MA customer service supports a less healthy, higher-need population with greater-than-average barriers to health care, and so should be designed and staffed to effectively serve medically complex, high-need patients. Commercial plan evidence suggests that continuity in customer service support for a member or a given issue may be helpful. Customer service is an important mechanism for improving quality and addressing health equity.