As Medicare’s annual open enrollment period begins, two new KFF analyzes suggest that a relatively small share of the nation’s 65 million Medicare beneficiaries will shop among the many coverage options for 2023 or switch plans. This decision could have a significant impact on coverage and costs for enrollees.

Results of a new KFF analysis show that only 3 in 10 beneficiaries (29%) compared their current plan with other Medicare plans offered during the open enrollment period for 2020.

The proportion of beneficiaries reviewing their coverage options was even lower among certain subgroups, including low-income beneficiaries (15%); enrolled in both Medicare and Medicaid (16%); 85 or older (18%); Hispanic (19%); or under 65 with a disability (22%).

A second KFF analysis finds that few beneficiaries choose to switch plans during open enrollment, whether enrolled in Medicare Advantage or traditional Medicare. For example, among people on Medicare Advantage with prescription drug coverage, only 1 in 10 beneficiaries enrolled in such plans voluntarily switched plans for 2020. Among traditional Medicare beneficiaries with a standalone drug plan, only 2 in 10 opted for a different plan during open registration.

(This analysis excluded beneficiaries who receive low-income subsidies for Part D coverage because they have a more limited set of choices and because some are automatically assigned to new plans each year by the government.)

Coverage and costs vary widely between Medicare Advantage plans and Part D prescription drug plans. From year to year, plans may change their premiums, cost-sharing requirements, and scope. covered drugs and additional benefits, as well as provider networks or pre-authorization requirements. These changes could lead to unexpected and avoidable costs and disruptions of care for beneficiaries who stay put and don’t at least review their options every year, as recommended by the Centers for Medicare & Medicaid Services (CMS).

Despite year-over-year changes in Medicare Advantage plans, about half (54%) of all Medicare Advantage enrollees have reviewed their current plan for potential changes in premiums or other out-of-pocket costs for coverage in 2020, while the other half did not, according to the study. The same proportion (54%) said they had reviewed their current plan for potential changes in the types of treatments, medications and services that would be covered the following year.

The analysis also reveals that official Medicare information resources are not widely used, particularly the 1-800-MEDICARE helpline. Just under half of beneficiaries (49%) said they had read all or part of the Medicare & You handbook, and 44% said they (or someone on their behalf) had visited the Medicare website .gov. Only 29% said they had called the helpline.

The two new KFF analyzes are based on the Medicare Beneficiary Survey and claims data from the Centers for Medicare & Medicaid Services.

For this data and other Medicare-related analysis, including our FAQs on open Medicare enrollment and our updated Medicare Part D prescription drug benefit overview, visit Medicare’s open enrollment period runs from October 15 through December 7.