Millions of Americans are entering the Medicare open enrollment season facing fewer Medicare Advantage plan options for 2027, making it increasingly important for seniors to review their health coverage before the deadline.

The annual enrollment window runs from October 15 through December 7, 2026. Eligible beneficiaries can switch between Original Medicare and Medicare Advantage, change private Medicare Advantage plans, or review and change their Medicare Part D prescription drug coverage.

According to healthcare policy research cited by MarketWatch, the average Medicare beneficiary will have access to 35 Medicare Advantage plans for 2027, down from 39 in 2026. At least 3.8 million current enrollees may need to find new coverage as insurers withdraw from certain markets or reduce their offerings.

Choosing a plan involves more than comparing monthly premiums. Beneficiaries should also check prescription costs, doctor and hospital networks, out-of-pocket limits, specialist referral requirements, and any changes outlined in their annual plan notices.

Coverage decisions made during open enrollment generally take effect on January 1, 2027.

With plan availability changing across the country, experts recommend comparing available options carefully and confirming coverage details directly with insurers or Medicare before making a decision.