That Medicare Letter in Your Mailbox Could Change What You Pay in 2027

Every fall, millions of Medicare beneficiaries receive a document that is easy to mistake for routine insurance mail. It is called the Annual Notice of Change, or ANOC, and ignoring it can become an expensive mistake. The notice explains how a Medicare Advantage or prescription drug plan will change when the new plan year begins in January, including changes to premiums, deductibles, copayments, covered drugs and other benefits.

The important point is that last year’s Medicare decision does not automatically remain the best one for 2027. Insurers are allowed to change plan costs and benefits from one year to the next, and provider and pharmacy networks can change as well. A plan that worked perfectly in 2026 could become substantially more expensive or less useful in January even if the beneficiary’s health has not changed.

The ANOC Is About the Plan You Already Have

The Annual Notice of Change is not a general Medicare brochure or an advertisement for every option available in the area. It comes from the beneficiary’s current plan and describes what will change in that specific coverage beginning Jan. 1.

Medicare says plans send ANOCs each fall, generally in September. The document should identify changes to costs, coverage and other plan rules so beneficiaries have time to decide whether their current coverage will still meet their needs during the next year. If the notice never arrives, Medicare advises contacting the plan directly.

That makes the ANOC one of the most important Medicare documents to review before Open Enrollment. The objective is not simply to see whether the premium went up. Beneficiaries should compare what they currently receive with what the plan will actually provide in 2027.

Start With the Premium—but Don’t Stop There

A monthly premium increase is easy to recognize because it immediately affects the household budget. But a plan can keep its premium unchanged while increasing costs elsewhere.

Hospital copayments may rise, specialist visits can become more expensive and deductibles can change. A Medicare Advantage plan’s maximum out-of-pocket limit can also change from year to year, which affects how much the beneficiary could potentially spend during a serious medical year.

That is why focusing only on the monthly premium can produce a false sense of security. A plan costing $0 a month may still expose a beneficiary to thousands of dollars in copayments and coinsurance as medical services are used.

The better comparison is total potential cost. Premiums, deductibles, copayments, drug expenses and out-of-pocket limits should all be considered together rather than evaluated as separate numbers.

Check Your Doctors and Hospitals Again

Provider access deserves the same scrutiny. Medicare Advantage plans can use provider networks, and Medicare notes that health plans can change which doctors, hospitals and pharmacies participate from year to year.

Someone who chose a plan specifically because a cardiologist, oncologist or hospital was in network should verify that relationship again for 2027. A provider listed last year may no longer participate, and assuming otherwise can create expensive surprises when care is needed.

The same applies to pharmacies. A prescription may cost considerably less at a plan’s preferred pharmacy than at another location. Beneficiaries who automatically continue using the same drugstore without checking the new plan rules can end up paying more even though the prescription itself has not changed.

Provider directories can also contain outdated information, so confirming participation with both the plan and the medical provider can provide additional protection before making a decision.

Prescription Coverage Can Change Even When Your Drugs Don’t

For people enrolled in Medicare Advantage plans with drug coverage or standalone Part D plans, the drug section of the ANOC deserves particular attention. Formularies—the lists of medications the plan covers—can change, as can the tier assigned to a particular drug.

A medication that was relatively inexpensive in 2026 might move to a different tier in 2027, require additional utilization controls or face different cost sharing. Preferred pharmacy arrangements can change as well.

This is one reason Medicare encourages beneficiaries to review coverage every year even when they are satisfied with their existing plan. The person may not have changed, but the insurance contract can.

Someone taking several ongoing medications should compare the entire drug list rather than simply looking at the plan premium. A small premium difference can easily be overwhelmed by higher prescription costs over the course of the year.

Your Plan Can Disappear Entirely

Sometimes the ANOC reveals something more significant than a price increase. An insurer can discontinue a particular Medicare Advantage or drug plan, leave a geographic market or move members into another plan under Medicare rules.

When a plan’s Medicare contract is not renewed, beneficiaries receive additional opportunities to change coverage. Medicare says people whose Medicare Advantage, drug or Cost plan is not renewed can generally switch during a Special Enrollment Period, and beneficiaries who do not select another Medicare Advantage plan may be returned to Original Medicare when the existing plan ends.

That makes plan termination different from an ordinary benefit adjustment. Someone receiving such a notice should not assume coverage will simply continue under the same terms.

The replacement option also deserves scrutiny. A plan that appears similar can still have different networks, drugs, copayments or benefits.

Oct. 15 Through Dec. 7 Is the Main Decision Window

Medicare Open Enrollment runs every year from Oct. 15 through Dec. 7. During that period, beneficiaries can join, drop or switch Medicare Advantage plans, move between Medicare Advantage and Original Medicare, or join, drop or change a standalone Medicare drug plan when eligible. Changes generally take effect Jan. 1.

One important misconception is that beneficiaries can make only one change during the fall enrollment period. Medicare’s rules do not impose that one-change restriction on the Oct. 15–Dec. 7 window. If someone submits more than one valid enrollment request during that period, the plan in effect for Jan. 1 is generally determined by the final valid enrollment request received by the deadline.

That flexibility can be useful when someone enrolls early and then discovers a better option before Dec. 7. It also creates a reason to keep records of every enrollment confirmation so there is no confusion about which plan was selected last.

If the current plan still meets the beneficiary’s needs and remains available, no action is generally required. Medicare says people who are satisfied with their existing coverage usually do not need to do anything for it to continue into the next plan year.

There Is Another Medicare Advantage Window After Jan. 1

People already enrolled in Medicare Advantage receive another opportunity to make a change during the Medicare Advantage Open Enrollment Period, which runs from Jan. 1 through March 31. During that period, they can switch to another Medicare Advantage plan or leave Medicare Advantage and return to Original Medicare.

Unlike the fall Open Enrollment Period, this window generally allows only one change. The new coverage takes effect on the first day of the month after the plan receives the request.

There are also important limitations. Someone in Original Medicare cannot use the January-through-March Medicare Advantage Open Enrollment Period to join Medicare Advantage, and a person with Original Medicare generally cannot use it simply to switch from one standalone drug plan to another.

That distinction matters because the two enrollment periods are often confused. Fall Open Enrollment is the broad annual shopping period; the first-quarter period is primarily a second chance for people already in Medicare Advantage.

Returning to Original Medicare Can Create a Medigap Problem

A beneficiary considering leaving Medicare Advantage should think beyond the decision to return to Original Medicare. Original Medicare does not have an annual out-of-pocket maximum for Part A and Part B services, which is why many beneficiaries also want a Medigap policy.

The complication is that Medicare Advantage enrollment and Medigap eligibility operate under different rules. After a person’s initial Medigap Open Enrollment Period ends, insurers generally may use medical underwriting unless the beneficiary qualifies for a federal guaranteed-issue right or additional protection under state law. Medicare warns that outside those protected circumstances, an insurer may charge more, offer fewer options or deny an application based on underwriting.

There are important federal trial rights. Someone who joined Medicare Advantage when first eligible for Medicare at 65 and decides within the first year to return to Original Medicare generally receives special rights to purchase certain Medigap policies. A person who dropped an existing Medigap policy to try Medicare Advantage for the first time may also have a limited right to recover that coverage if returning within the first year.

That means “I’ve been in Medicare Advantage for more than a year, so I definitely need underwriting” is too broad, just as “I can always go back to Medigap” is too broad. Federal guaranteed-issue circumstances and additional state protections can change the answer.

State Rules Can Be More Generous

Federal law establishes a baseline for Medigap protections, but states can provide additional rights. Medicare specifically advises beneficiaries to check with their State Insurance Department because some states allow broader opportunities to purchase or switch Medigap coverage outside the federal open-enrollment protections.

That makes state-specific advice especially important for anyone considering leaving Medicare Advantage. Rules that apply in Pennsylvania may differ from protections available in New York, Connecticut, Massachusetts or another state.

The safest approach is to determine Medigap eligibility before dropping Medicare Advantage when supplemental coverage is important. Returning to Original Medicare first and only then discovering that the preferred Medigap policy is unavailable can leave the beneficiary with an unintended coverage structure.

Plan timing should therefore be coordinated carefully so one policy does not disappear before the replacement has been confirmed.

Don’t Forget Standalone Part D Plans

People using Original Medicare with a standalone prescription drug plan should review their ANOC just as carefully as Medicare Advantage members. Drug-plan premiums, deductibles, formularies, pharmacy networks and copayments can all change annually.

During the Oct. 15–Dec. 7 Open Enrollment Period, beneficiaries in Original Medicare can switch from one drug plan to another for the coming year. The current coverage generally remains in place through Dec. 31, with the new plan taking effect Jan. 1 when enrollment is completed on time.

This annual comparison can be particularly valuable because prescription needs change. A plan that was cheapest when someone took two generic medications may no longer be competitive after a new brand-name drug is prescribed.

The cheapest premium is therefore not necessarily the cheapest Part D option overall. What matters is the combined cost of premiums and the medications the individual actually uses.

Be Careful About Who Helps You Choose

Medicare beneficiaries can enroll directly through Medicare, work with insurance companies or seek assistance from licensed agents and brokers. There is nothing inherently wrong with any of those routes, but consumers should understand whom the person helping them represents.

A captive agent may primarily represent one insurer, while an independent broker can potentially offer products from multiple companies. That does not automatically make one adviser better than another, and the specific contracts available to an independent agent can still vary.

Consumers should ask whether the person can discuss all of the plans relevant to their situation, how the person is compensated and what ongoing service is provided after enrollment. Commission arrangements can differ among plans, so transparency matters more than assuming every agent has identical financial incentives.

Beneficiaries who want help without an insurance sales relationship can also use their State Health Insurance Assistance Program, commonly known as SHIP. Medicare describes SHIP counselors as independent from insurance companies and health plans.

The ANOC Is a Warning, Not Junk Mail

Medicare coverage is not a decision someone makes once at 65 and never revisits. Plans operate on annual contracts, and benefits, networks, drug coverage and costs can change every January.

The ANOC provides an early warning. It tells beneficiaries what their existing plan intends to change before Open Enrollment begins, giving them time to determine whether the coverage still fits their doctors, prescriptions and finances.

For someone whose premium barely changes and whose providers and medications remain covered, doing nothing may be perfectly reasonable. For someone facing a disappearing doctor, a formulary change or substantially higher cost sharing, the same document can provide the information needed to avoid a costly year.

That is why the most important Medicare task every fall may be surprisingly simple: open the envelope.

Read the ANOC, compare the changes with the coverage actually being used and make a deliberate decision before Dec. 7. Medicare plans can change every year, and retirement health coverage should not be left on autopilot.