Millions of older Americans may need to choose new health coverage for 2027 after insurers announced they are withdrawing Medicare Advantage plans from communities across the country. Medicare’s annual open enrollment period runs through Dec. 7. At least 2 million people are expected to be affected by plan closures, while preliminary estimates put the number as high as 5 million. About 35 million people are enrolled in Medicare Advantage. The pullbacks reach rural counties and major cities alike. A KFF analysis of federal data found that 193 counties will have no Medicare Advantage plans available next year, up from about 120 counties this year. Dallas, Minneapolis, Seattle, Houston and Portland are each expected to have between one-quarter and one-third fewer plans. Medicare Advantage is administered by private insurers rather than directly by the federal government. More than half of the roughly 70 million Americans on Medicare choose it. The plans are popular in part because they often include vision and dental benefits, prescription drug coverage and lower premiums than traditional Medicare. But insurers decide where to offer plans, and companies can leave markets they consider unprofitable. Research published in JAMA found that closures have grown in scale over the past three years. Last year, 2.9 million seniors were enrolled in plans that closed. Seniors whose plans are ending should check notices from their insurers or log in to Medicare.gov to confirm their coverage for next year. If they do not choose a new plan, they may be assigned to another Medicare Advantage plan or moved to traditional Medicare without a supplemental or prescription drug plan. People whose Medicare Advantage coverage is ending can also qualify for a special enrollment period to buy a Medigap supplemental plan without the usual restrictions, including restrictions that can affect people with pre-existing conditions. The special period runs through Feb. 28, 2027. To have new coverage start Jan. 1, people need to enroll by Dec. 31. There is another reason not to wait: insurers may limit enrollment in some plans for 2027. Those plans are supposed to accept customers on a first-come, first-served basis, without screening by age, health status or demographics. A plan that appears suitable could fill before a senior signs up. Free, unbiased help is available through each state’s State Health Insurance Assistance Program, or SHIP. Seniors can find local assistance at shiphelp.org. Medicare’s online Plan Finder can help compare options, but provider and drug lists may be inaccurate, so consumers should confirm coverage with doctors or a counselor. Seniors should also be cautious about sharing personal information with online services that may sell it and trigger sales calls or scams.