Medicare Advantage Part B Premium Givebacks and Enrollment.

IMPORTANCE

In Medicare Advantage (MA), the private component of the Medicare program that enrolls more than half of beneficiaries, an increasing share of plans are offering Part B premium givebacks to pay for part or all of the at least $174.70 Part B monthly premium. Millions of dollars of Medicare expenditures are attributable to this benefit, yet little is known about its association with member enrollment or other plan characteristics.

OBJECTIVE

To document trends and expenditures in MA Part B premium givebacks and examine their association with plan enrollment.

DESIGN, SETTING, AND PARTICIPANTS: This longitudinal difference-in-differences analysis compared MA plan enrollment before and after the offer of a Part B giveback among plans that offered the giveback vs plans that did not. January MA plan enrollment and characteristics data from 2018 through 2024 were included. Data were analyzed from May 2024 to February 2025.

EXPOSURE

Adoption of a Part B giveback.

MAIN OUTCOMES AND MEASURES

Total plan enrollment.

RESULTS

A sample of 18 627 plan-years representing more than 130 million enrollee-years was included in the analysis. The percentage of MA plans offering a Part B premium giveback increased from 4.3% (93 of 2187) in 2018 to 18.7% (737 of 3940) in 2024. Plans offering Part B premium givebacks had lower median enrollment, belonged to newer, higher rated contracts, had higher cost-sharing, and had lower enrollee risk scores compared with plans that did not offer givebacks. In 2024, the 3.4 million enrollees in plans with Part B givebacks received a mean (SD) of $77 ($42), amounting to as much as approximately $261 million in total monthly expenditures across the MA program. Adoption of a Part B giveback was associated with a 33.3% (95% CI, 9.3-56.9) increase in enrollment, robust to all model specifications. There was a dose-response association between the size of the giveback and enrollment.

CONCLUSIONS AND RELEVANCE

In this study, the adoption of Part B premium givebacks among MA plans was associated with a substantial increase in plan enrollment. Further research will be needed to understand the total value to enrollees of Part B givebacks, which confers hundreds of millions of dollars monthly to Medicare beneficiaries.