Medicare Switching: Patterns Of Enrollment Growth In Medicare Advantage, 2006-22.

Medicare Advantage (MA) has grown rapidly over the course of the past two decades and is projected to continue to grow. We examined sources of new enrollment in MA and analyzed the switching patterns between MA and traditional fee-for-service Medicare, using more recent and more detailed data than in previous analyses. We found that switching from fee-for-service Medicare to MA more than tripled between 2006 and 2022, whereas switching from MA to fee-for-service Medicare decreased, with the change rates accelerating since 2019. The share of switchers among all new MA enrollees rose from 61 percent in 2011 to 80 percent in 2022. Black, dual-eligible, and disabled beneficiaries had higher odds of switching in both directions, whereas younger and healthier beneficiaries had higher odds of switching from fee-for-service Medicare to MA but lower odds of switching from MA to fee-for-service Medicare. Two-thirds of annual switching between MA and fee-for-service Medicare in 2022 occurred in January, likely reflecting the open enrollment period.