ABSTRACT: Importance:How often enrollees with complex care needs leave the Medicare Advantage (MA) program and what might drive their decisions remain unknown. Objective:To characterize trends in switching to and from MA among high-need beneficiaries and to evaluate the drivers of disenrollment decisions. Design, Setting, and Participants:This cross-sectional study of MA and traditional Medicare (TM) enrollees from January 1, 2014, through December 31, 2015, used a multinomial logit regression stratified by Medicare-Medicaid eligibility status. All 14?589?645 non-high-need MA enrollees and 1?302?470 high-need enrollees in the United States who survived until the end of 2014 were eligible for the analysis. Data were analyzed from November 1, 2017, through August 1, 2018. Exposures:Enrollee dual eligibility and high-need status (based on complex chronic conditions, multiple morbidities, use of health care services, functional impairment, and frailty indicators), MA plan star rating, and cost sharing. Main Outcomes and Measures:The proportion of enrollees who disenrolled into TM, remained in the same MA plan, or who switched plans within the MA program. Results:A total of 13 901 816 enrollees were included in the analysis (56.2% women; mean [SD] age, 70.9 [9.9] years). Among the 1?302?470 high-need enrollees, an adjusted 4.6% (95% CI, 4.5%-4.6%) of Medicare-only and 14.8% (95% CI, 14.5%-15.0%) of Medicare-Medicaid members switched from MA to TM compared with 3.3% (95% CI, 3.3%-3.3%) and 4.6% (95% CI, 4.5%-4.7%), respectively, among non-high-need enrollees. Among enrollees in low-quality plans, 23.0% (95% CI, 22.3%-23.9%) of Medicare and 42.8% (95% CI, 40.5%-45.1%) of dual-eligible high-need enrollees left MA. Even in high-quality plans, high-need members disenrolled at higher rates than non-high-need members (4.9% [95% CI, 4.6%-5.2%] vs 1.8% [95% CI, 1.8%-1.9%] for Medicare-only enrollees and 11.3% vs 2.4% dual eligible enrollees). Enrollment in a 5.0-star rated plan was associated with a 30.1-percentage point reduction (95% CI, -31.7 to -28.4 percentage points) in the probability of disenrollment among high-need individuals. A $100 increase in monthly premiums was associated with a 33.9-percentage point increase (95% CI, -34.9 to -33.0 percentage points) in the likelihood of switching plans, and a small reduction in the likelihood of disenrolling (-2.7 percentage points; 95% CI, -3.2 to -2.2 percentage points). Among Medicare-Medicaid eligible participants, 14.1% (95% CI, 14.0%-14.2%) of high-need and 16.7% (95% CI, 16.6%-16.7%) of non-high-need enrollees switched from TM to MA. Conclusions and Relevance:Results of this study suggest that substantially higher disenrollment from MA plans occurs among high-need and Medicare-Medicaid eligible enrollees. This study's findings suggest that star ratings have the strongest association with disenrollment trends, whereas increases in monthly premiums are associated with greater likelihood of switching plans.
