Medicare Advantage enrollment can look straightforward from the outside—select a plan, confirm your coverage, move on. In practice, the decisions involved carry real financial and healthcare consequences that play out over the entire plan year. Thousands of enrollees make avoidable mistakes each year that result in higher costs, disrupted care, and limited access to services they expected to receive. Avoiding these errors starts with understanding them. As you evaluate options for 2027, knowing what to watch for is just as important as knowing what to look for in the best Medicare Advantage plans 2027.
1: Choosing Based on Premium Alone
A low or $0 monthly premium is appealing, but it tells an incomplete story. Plans with no monthly premium often carry higher deductibles, elevated copayments, and lower out-of-pocket maximums than plans with modest premiums.
Calculate your estimated total annual cost—including premiums, copays, and drug costs—before selecting a plan. The lower-premium option is frequently not the lower-cost option.
2: Not Verifying That Your Doctors Are In-Network
Provider networks change every year. A physician who was in-network under your plan in 2026 may not be listed in 2027. Assuming continuity without verification can result in out-of-network charges or the need to find a new provider mid-year.
Confirm each of your key providers—primary care, specialists, and hospital systems—directly with the plan before enrolling.
3: Ignoring the Drug Formulary
Prescription drug coverage is one of the most impactful and most overlooked variables in Medicare Advantage selection. Plans organize drugs into cost tiers, and the same medication can carry vastly different cost-sharing requirements depending on which plan covers it and at what tier.
Search each plan’s formulary for every medication you currently take before making a final decision.
4: Overlooking the Out-of-Pocket Maximum
Every Medicare Advantage plan is required to set an annual out-of-pocket maximum for covered in-network services. In 2024, these maximums ranged from under $2,000 to as high as $8,850. The difference between the lowest and highest figures represents thousands of dollars in potential exposure if a serious health event occurs.
Comparing out-of-pocket maximums across plans is one of the most effective ways to assess financial risk.
5: Forgetting to Check the Plan’s Star Rating
CMS rates Medicare Advantage plans annually on a 1-to-5-star scale based on quality of care, member satisfaction, and chronic condition management. Plans rated 4 stars or higher consistently demonstrate stronger outcomes and member experience.
Relying on last year’s star rating can mislead you. CMS updates ratings annually, and plans can move in either direction. Always check the current rating during open enrollment.
6: Assuming Supplemental Benefits Will Stay the Same
Dental allowances, vision coverage, fitness memberships, and over-the-counter product credits are among the supplemental benefits that attract many enrollees to Medicare Advantage. These benefits are not guaranteed to remain the same year over year.
Review the Summary of Benefits for your plan’s 2027 offering specifically. Do not assume that a benefit you received in 2026 will carry forward at the same value.
7: Missing the Enrollment Window
The Annual Enrollment Period runs from October 15 to December 7. Changes made during this period take effect January 1, 2027. Missing this window without a qualifying Special Enrollment Period means you are locked into your current plan for another full year—even if that plan no longer meets your needs.
Set a calendar reminder and begin your plan research in September, before the enrollment period opens. Reviewing your Annual Notice of Change document—which insurers must mail to members by September 30—gives you a head start on understanding what’s changing in your current plan.
Make 2027 the Year You Get Coverage Right
Each of these mistakes is preventable with a structured, proactive approach to plan selection. Start with your health priorities, verify the details, and compare options side by side before the December 7 deadline. The right Medicare Advantage plan for 2027 is out there—finding it just requires asking the right questions before you sign up.
