Medigap Enrollment Patterns Before and After Ban on New Medigap Plan F Enrollment

ABSTRACT

Objectives: Medigap plays a central role in providing cost-sharing support and protections from unexpected catastrophic spending for non–dually eligible enrollees in traditional Medicare (TM). We examine Medigap enrollment patterns before and after the 2020 federal policy prohibited newly eligible Medicare beneficiaries from enrolling in Medigap Plan F.

Study Design: We quantified annual national trends in Medigap enrollment overall and by standardized Medigap plan from 2013 through 2024.

Methods: We used the Mark Farrah Associates’ Medicare Supplement insurance data to measure individual Medigap enrollment by standardized Medigap plan and year and supplemented with publicly available TM enrollment data. We calculated a percentage using total individual Medigap enrollment as the numerator and the number of non–dually eligible TM beneficiaries as the denominator.

Results: Although total individual Medigap enrollment decreased starting in 2022, Medigap enrollment represented 29% of the non–dually eligible TM population in 2013 and 47% in 2024. This in part reflects the diminishing size of the non-dually eligible TM enrollee population, which numbered 25 million in 2013 and 19 million in 2024. In 2019, the year before the policy change, Medigap Plan F was the most common plan, enrolling 50% of individual Medigap enrollees, compared with Medigap Plan G, enrolling 28% of individual Medigap enrollees. Plan G overtook Plan F as the most common plan in 2022. By 2024, Plan G was the most popular plan, enrolling 48% of Medigap enrollees, followed by Plan F (34%) and Plan N (10%).

Conclusions: Together, these trends suggest that first-dollar coverage of the Part B deductible has declined as enrollment has shifted from Plan F to Plan G.

Am J Manag Care. 2026;32(11):610-612

doi:10.37765/ajmc.2026.90039

Takeaway Points

Policy makers and practitioners should recognize that Medigap reforms can shape supplemental coverage patterns, catastrophic spending protections, and first-dollar coverage for traditional Medicare (TM) beneficiaries.

• After newly eligible beneficiaries were barred from enrolling in Plan F in 2020, total individual Medigap enrollment declined slightly starting in 2022, but individual Medigap enrollment as a share of non–dually eligible TM beneficiaries increased, potentially reflecting changes in the composition of TM enrollees.
• The proportion of Medigap enrollees in a nongroup Plan G has risen over the past decade from 11% in 2015 to 48% in 2024.
• Policy makers should monitor Medigap standardized plan enrollment and affordability to ensure access to supplemental coverage for TM beneficiaries.

Traditional Medicare (TM) beneficiaries face financial risk because TM imposes cost sharing (eg, 20% coinsurance for outpatient services) and lacks an out-of-pocket maximum. Though Medicaid covers cost sharing for beneficiaries dually-eligible for both Medicaid and Medicare, non–dually eligible beneficiaries can mitigate only some financial risk by purchasing supplemental insurance (Medigap). Medigap plans cover varying portions of out-of-pocket costs, organized under a letter-based naming system.¹ Plan F, the most generous plan, covers 100% of TM beneficiary cost-sharing responsibilities, whereas Plan G, the next most generous, differs only in that it does not cover the Part B deductible. Medigap coverage is therefore central to unexpected catastrophic spending protections and cost-sharing support for TM beneficiaries.²

To address excess spending concerns,³ federal policy prohibited newly eligible Medicare beneficiaries from enrolling in Medigap Plan F starting on January 1, 2020.⁴ This policy also prohibited newly eligible Medicare beneficiaries from enrolling in Medigap Plan C, which was nearly as generous as Plan F, though not nearly as popular. After this policy, newly eligible beneficiaries had to choose among less generous Medigap plans. This policy change may be associated with Medigap enrollment trends.

We examined national trends in overall and plan-specific individual (ie, nongroup and nonemployer) Medigap enrollment from 2013 to 2024, including before and after the discontinuation of Medigap Plan F for newly eligible beneficiaries.

METHODS

This study followed the Strengthening the Reporting of Observational Studies in Epidemiology reporting guidelines. Institutional review board approval was not sought because no human participants were involved.

We used Medicare Supplement Insurance market data from Mark Farrah Associates to measure Medigap enrollment by standardized plan type (“Standardized Plan” variable; did not distinguish by special plan type) and year,⁵ and supplemented with publicly available data from the CMS Medicare Monthly Enrollment Dashboard. We calculated the percentage using total Medigap enrollment as the numerator and the number of non–dually eligible TM beneficiaries (subtracting total dually eligible TM Part A and Part B beneficiaries from total TM Part A and Part B beneficiaries) as the denominator.

Our sample included individual Medigap plans that were not offered by a group or employer operating in 47 US states with standardized Medigap plans and the District of Columbia with at least 10 enrollees each year. Our non–dually eligible TM beneficiary sample was restricted to those residing in those same 47 states or the District of Columbia.

We examined annual national trends in individual Medigap enrollment overall and by standardized Medigap plan from 2013 through 2024.

RESULTS

Total individual Medigap plan enrollment was 7.2 million in 2013 and grew to 9.4 million in 2019, remained at 9.4 million through 2021, and then decreased to 9.1 million in 2024. Total Medigap enrollment represented 29% of the non–dually eligible TM population in 2013 and 47% in 2024 (Figure 1). This in part reflects the diminishing size of the non–dually eligible TM enrollee population, which numbered 25 million in 2013 and 19 million in 2024.

The distribution of enrollment among individual Medigap plan types has changed over time. Before the 2020 policy change, Plan G had been growing relative to Plan F, with G growing from 7% to 28% of individual Medigap enrollment between 2013 and 2019 and F shrinking from 56% to 50%. In 2021, after Plan F was discontinued for newly eligible beneficiaries, Plan F enrollment continued its decline, decreasing by 8 percentage points relative to 2019, whereas Plan G enrollment increased by 9 percentage points. Plan G overtook Plan F as the most common plan in 2022 and by 2024, 48% of nongroup Medigap enrollment was in Plan G, followed by Plan F (34%) and Plan N (10%) (Figure 2).

DISCUSSION

We observe 3 main findings. First, total individual (ie, nongroup and nonemployer) Medigap enrollment decreased after the 2020 policy change. Second, despite this decline, total individual Medigap enrollment grew relative to the non–dually eligible TM population from 2013 to 2024. Third, enrollees have chosen different types of Medigap plans over time: An increasing proportion of individual Medigap enrollees have enrolled in Plan G, consistent with a continuing shift toward Plan G that predated Plan F’s closure to newly eligible beneficiaries.

Together, these trends suggest that TM beneficiaries’ financial protections have evolved: Fewer enrollees receive Part B deductible coverage as enrollment in Plan F has declined. With that said, the share of individual Medigap enrollees in Plan G was steadily increasing before 2020. Future work should assess the causal effects of Plan F’s discontinuation on coverage choices, including Medicare Advantage,⁶ and focus on directly affected newly eligible Medicare beneficiaries, as aggregate trends combine newly eligible beneficiaries with grandfathered Plan F enrollees.

Author Affiliations: Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health (AL), Baltimore, MD; University of Southern California Schaeffer Center for Health Policy & Economics (GM, ET), Los Angeles, CA.

Source of Funding: Dr Liu was funded by Arnold Ventures grant G146501, and Drs Mackleby and Trish were funded by Arnold Ventures grant 25-14304. The content is solely the responsibility of the authors and does not necessarily represent the official views of Arnold Ventures.

Author Disclosures: Dr Liu reports receiving fees from Robbins Geller Rudman & Dowd LLP for unrelated work. Dr Trish works as a consultant and litigation expert on matters related to hospitals, health insurance, health information technology, public health, and life sciences. She is also funded by a Student Empowerment Award from the University of Southern California Office of Research and Innovation. The authors report no relationship or financial interest with any entity that would pose a conflict of interest with the subject matter of this article.

Authorship Information: Concept and design (AL, GM); acquisition of data (AL); analysis and interpretation of data (AL, GM, ET); drafting of the manuscript (AL); critical revision of the manuscript for important intellectual content (AL, GM, ET); statistical analysis (AL, ET); provision of patients or study materials (AL); and administrative, technical, or logistic support (AL, ET).

Address Correspondence to: Angela Liu, PhD, Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St, Office W7503C, Baltimore, MD 21205. Email: aliu63@jh.edu.

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