Medicare open enrollment is officially underway, giving millions of Americans until December 7 to review their healthcare coverage and make changes for 2027. For retirees, overlooking this deadline could mean higher medical bills, unexpected prescription costs, or losing access to preferred doctors.
The annual enrollment period began October 15 and runs through December 7, 2026. Any changes made during this window will take effect January 1, 2027.
Even retirees who are happy with their current Medicare coverage should take another look. Insurance companies can change premiums, deductibles, prescription drug coverage, provider networks, and other benefits each year.
Keeping the same plan without reviewing those changes could turn into an expensive mistake.
Medicare Beneficiaries Have Fewer Plans to Choose From in 2027
According to healthcare research organization KFF, the average Medicare beneficiary will have access to 35 Medicare Advantage plans in 2027, down from 39 in 2026.
Although retirees still have plenty of choices, fewer available plans can make comparing coverage especially important.
During the October 15 through December 7 enrollment period, beneficiaries can:
- Switch from Original Medicare to Medicare Advantage.
- Switch from Medicare Advantage back to Original Medicare.
- Change from one Medicare Advantage plan to another.
- Join, drop, or switch Medicare Part D prescription drug plans, subject to their existing coverage.
For beneficiaries who do nothing, existing coverage generally renews automatically if the plan continues to operate. However, its costs and benefits may change for 2027.
That makes reviewing the details important, even when no plan switch is necessary.
Many Retirees Are Not Reviewing Their Medicare Coverage
A new University of Michigan National Poll on Healthy Aging suggests millions of older Americans may be overlooking opportunities to improve their coverage.
The survey found that 27% of Medicare beneficiaries did not review their coverage options before or during the enrollment period for 2026.
Another 33% spent less than an hour reviewing their options, while 40% spent an hour or more.
The survey also found that 80% of Medicare beneficiaries kept the same coverage for 2026.
For many, the decision came down to satisfaction with their existing plan. In fact, 96% of respondents with Medicare coverage in 2025 reported being at least somewhat satisfied with it.
But satisfaction with last year’s coverage does not guarantee the same costs or benefits next year.
Five Things Retirees Should Check Before December 7
The biggest financial risk during Medicare enrollment is choosing a plan based entirely on its monthly premium.
A plan with a lower premium could ultimately cost more if it carries higher deductibles, expensive prescription copays, or limited access to doctors.
Before deciding whether to switch plans, retirees should review five important areas.
1. Monthly Premiums and Out-of-Pocket Costs
Compare the total estimated annual cost of coverage, including premiums, deductibles, copays, and coinsurance.
For Medicare Advantage plans, pay particular attention to the annual out-of-pocket maximum for covered Part A and Part B services.
2. Prescription Drug Coverage
Check whether existing medications remain covered in 2027 and whether they have moved into more expensive pricing tiers.
Also review preferred pharmacies, deductibles, and restrictions that could affect how prescriptions are filled.
3. Doctor and Hospital Networks
Medicare Advantage plans often use provider networks. A doctor or hospital covered in 2026 might no longer participate in the same plan for 2027.
Retirees who see specialists regularly should confirm that their preferred providers will remain available.
4. Changes to Additional Benefits
Some Medicare Advantage plans offer dental, vision, hearing, transportation, and other supplemental benefits.
These benefits can change annually, so retirees should compare what they actually use rather than focusing on advertised extras.
5. Expected Healthcare Needs
A retiree planning surgery, specialist treatment, or a change in medication should consider those needs when choosing coverage.
A plan that worked well during a relatively healthy year may become considerably more expensive when medical needs increase.
Switching Between Medicare Advantage and Original Medicare Requires Extra Caution
One of the most important decisions retirees face is whether to remain in Medicare Advantage or switch to Original Medicare.
Original Medicare generally allows beneficiaries to visit any doctor or hospital nationwide that accepts Medicare. Medicare Advantage plans typically operate through private insurance companies and may have narrower provider networks.
However, switching from Medicare Advantage back to Original Medicare can create another issue: supplemental coverage.
Many retirees purchase Medicare Supplement Insurance, commonly called Medigap, to help cover deductibles and other expenses that Original Medicare does not fully pay.
Outside certain enrollment periods or guaranteed-issue situations, insurers may be allowed to deny a Medigap application or charge more based on health history, depending on state law.
Retirees considering this move should confirm their Medigap eligibility before giving up existing coverage.
Missing Medicare Deadlines Can Also Trigger Permanent Penalties
The October 15 through December 7 period is primarily for people who already have Medicare and want to adjust their coverage.
Other enrollment windows apply to people signing up for Medicare for the first time or dealing with changes in their circumstances.
| Enrollment Period | Important Dates |
|---|---|
| Annual Open Enrollment | October 15–December 7 |
| Initial Enrollment | Seven-month window around turning 65, in most cases |
| General Enrollment | January 1–March 31 |
| Medicare Advantage Open Enrollment | January 1–March 31 |
| Special Enrollment | Varies by qualifying event |
Missing an initial Medicare enrollment deadline can carry lasting financial consequences.
For example, people who delay enrolling in Medicare Part B without qualifying for an exception generally face a 10% premium penalty for every full 12-month period they were eligible but did not enroll.
Someone who delays Part B enrollment for two full years could face a 20% increase in their monthly Part B premium. That additional cost generally continues for as long as they have Part B coverage.
Certain beneficiaries who remain covered through qualifying employer health insurance can delay enrollment without facing these penalties.
There Is Another Chance to Change Medicare Advantage Plans in 2027
Retirees who miss the December deadline may have another opportunity to adjust their coverage, depending on the type of plan they have.
The Medicare Advantage Open Enrollment Period runs from January 1 through March 31, 2027.
During that window, individuals already enrolled in Medicare Advantage can switch to another Medicare Advantage plan or return to Original Medicare. Those returning to Original Medicare can also join a standalone prescription drug plan.
However, this enrollment period does not allow beneficiaries with Original Medicare to join Medicare Advantage.
Individuals who experience qualifying life events, including moving or losing certain health insurance coverage, may also be eligible for a special enrollment period.
How to Compare Medicare Plans Before the Deadline
The simplest place to begin is Medicare’s official Plan Finder at Medicare.gov.
Beneficiaries can compare plans available in their ZIP code, enter prescription medications, review estimated costs, and evaluate coverage options for 2027.
Retirees should also review the Annual Notice of Change sent by their current insurance company. This document explains changes to coverage and costs taking effect in January.
Those who need additional assistance can contact Medicare at 1-800-MEDICARE or use their State Health Insurance Assistance Program for free, personalized counseling.
The key is to compare total annual expenses and access to care rather than simply choosing the plan with the lowest advertised premium.
The Takeaway for Retirees
Medicare open enrollment gives retirees an opportunity to review one of their most important household expenses before 2027.
With plan availability changing and healthcare costs remaining a major concern for older Americans, taking time to compare coverage could help avoid unnecessary expenses.
The December 7 deadline is approaching, and even retirees planning to keep their existing Medicare coverage should review their options before it passes.
A relatively small amount of time spent reviewing premiums, prescription coverage, and provider networks today could help prevent much larger medical bills next year.
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