Medicare Enrollment Periods: A Wisconsin Guide

Quick Summary: The Initial Enrollment Period (IEP) generally runs from three months before the month you turn 65 through three months after it. The Annual Election Period (AEP) runs every year from October 15 through December 7 and is used to change Medicare Advantage or Part D coverage for January 1. A Special Enrollment Period (SEP) is triggered by qualifying life events and has dates that vary by situation. The one-time Medigap Open Enrollment Period (OEP) lasts six months beginning when you are age 65 or older and enrolled in Medicare Part B, and it is the key window for buying Medicare Supplement coverage without health underwriting.

Medicare enrollment is full of deadlines, acronyms, and rules that can feel needlessly complicated. At Red Sky Insurance Advisors, Ryan Olson helps Wisconsin residents understand which enrollment window applies to them, what choices they can make, and what can happen if they wait too long. The right timing can protect both your coverage options and your budget.

1. Initial Enrollment Period: Your First Medicare Window

Your IEP is usually a seven-month window: the three months before your 65th-birthday month, your birthday month, and the three months after it. For example, if you turn 65 on June 15, your IEP generally runs from March 1 through September 30. If your birthday is on the first day of a month, Medicare uses a slightly different schedule, so confirm your exact dates early.

This is the time to enroll in Original Medicare Parts A and B if you are not automatically enrolled, and to decide whether a Medicare Advantage plan or Original Medicare paired with a Medicare Supplement and Part D prescription drug plan is right for you. Starting early matters: enrolling before your birthday month can help coverage begin on time and avoid an unwanted gap.

Missing the IEP can be expensive. If you delay Part B without qualifying for an SEP, you may have to wait for the General Enrollment Period, which runs January 1 through March 31 each year, with coverage generally starting the month after you enroll. You may also owe a Part B late enrollment penalty: typically an additional 10% of the standard Part B premium for every full 12-month period you could have had Part B but did not. In most cases, that penalty lasts as long as you have Part B.

Part D has its own lasting consequence. Going 63 days or more without Medicare drug coverage or other creditable prescription drug coverage can trigger a late enrollment penalty. That penalty is generally 1% of the national base beneficiary premium for each full month you went without qualifying drug coverage, and it is usually added to your Part D premium for as long as you have Part D.

2. Annual Election Period: October 15 Through December 7

AEP, often called Medicare Open Enrollment, occurs every year from October 15 through December 7. Changes made during this period take effect January 1. It is the annual opportunity for many people with Medicare to review and change their Medicare Advantage plan, change or join a standalone Part D plan, move from Original Medicare to Medicare Advantage, or return from Medicare Advantage to Original Medicare.

This is not the same as enrolling in Part B for the first time, and it is not a guaranteed opportunity to buy a Medigap policy without underwriting. Instead, AEP is primarily a plan-review window. Prescription formularies, pharmacy networks, provider networks, premiums, copays, and benefits can all change from year to year. That is why an Annual Plan Review can be so valuable.

If you miss December 7, you will generally need to keep your current coverage for the following year unless you qualify for an SEP. For Wisconsin residents, that can mean another year in a plan that no longer includes a preferred doctor, pharmacy, medication, or benefit structure. Ryan Olson encourages clients to review their Annual Notice of Change as soon as it arrives rather than waiting until the deadline week.

3. Special Enrollment Periods: Coverage Changes After Life Changes

SEPs create enrollment opportunities outside the usual calendar windows after certain life events. The exact actions you can take and the length of your SEP depend on why you qualify. Common examples include moving outside your plan’s service area, losing other creditable coverage, changes to a plan’s contract with Medicare, qualifying for Extra Help or Medicaid, or certain exceptional circumstances.

One especially important SEP applies when you or your spouse has coverage from current employment. In many cases, you can delay Part B while that qualifying employer group coverage remains in place, then enroll during an eight-month SEP that begins the month after employment ends or the group coverage ends, whichever happens first. This rule deserves careful attention: COBRA, retiree coverage, VA coverage, and Marketplace coverage do not count as current-employment group coverage for this Part B SEP.

Missing an SEP can put you back into the General Enrollment Period for Part B and may expose you to the permanent Part B penalty. It can also leave you without an available window to change Medicare Advantage or Part D coverage. Before leaving a job, moving, or dropping any health plan, talk with an independent Medicare broker in Wisconsin about the dates that apply to your situation.

4. Medigap Open Enrollment: A Separate, One-Time Opportunity

The Medigap OEP is different from AEP. It is a one-time, six-month period that begins on the first day of the month when you are both 65 or older and enrolled in Part B. During this period, you can purchase any Medicare Supplement policy sold in your state without being denied or charged more because of current or past health conditions.

For many people choosing Original Medicare, this is the most important time to compare Medicare Supplement options. After the six months end, insurers may generally use medical underwriting unless you have a guaranteed-issue right. That can mean fewer choices, higher premiums, or a declined application depending on your health and the policy you want.

5. Wisconsin Medigap Rules and Guaranteed-Issue Protections

Wisconsin has its own Medicare Supplement structure, including the Wisconsin Medicare Supplement base plan and optional riders. That makes local guidance especially helpful; the letter-plan comparisons people see in national Medicare discussions do not always translate directly to how Wisconsin Medigap coverage is organized. You can start with Red Sky Insurance Advisors’ Medicare Overview for a high-level look at the available paths.

During Wisconsin’s six-month Medigap OEP, carriers must make coverage available regardless of health status. Wisconsin also provides guaranteed-issue protections in certain qualifying situations outside that window, such as when a Medicare Advantage or Cost plan leaves your service area, an employer group plan ends, certain Medicare Supplement coverage ends through no fault of your own, or you exercise qualifying trial rights after leaving a plan. These protections are time-sensitive. In many situations, an application must be made no later than 63 calendar days after the other coverage ends.

Guaranteed issue is powerful, but it is not automatic and it is not available after every voluntary plan change. Keep termination notices and other proof of prior coverage, and get advice before canceling a Medigap policy or leaving a Medicare Advantage plan. Once coverage is dropped, getting the same protection back may not be simple.

6. A Practical Medicare Deadline Checklist

• Mark your IEP well before your 65th birthday month.
• Confirm whether employer coverage is based on current employment and whether drug coverage is creditable.
• Review your Medicare plan each fall before the October 15–December 7 AEP deadline.
• Do not confuse AEP with your six-month Medigap OEP.
• Before a move, retirement, loss of coverage, or plan cancellation, ask whether an SEP or guaranteed-issue right applies.

FAQ

Do I have to enroll in Medicare at 65 if I am still working?

Not always. The answer depends on the size and type of your employer coverage, whether it is based on current employment, and whether your prescription drug coverage is creditable. Get guidance before delaying Part B or Part D.

Can I switch Medigap plans during AEP?

You may apply, but AEP does not create a universal right to buy a Medigap policy without underwriting. Your Medigap OEP and any guaranteed-issue rights are separate rules.

Is the Part B late enrollment penalty permanent?

For most people who do not qualify for an SEP, yes. The Part B penalty generally continues for as long as you have Part B.

Is the Part D penalty permanent?

It is generally added to your Part D premium for as long as you have Medicare drug coverage, and the dollar amount can change as the national base beneficiary premium changes.

Get Help Before a Deadline Passes

Medicare deadlines are easier to manage when you have a plan before the clock starts. Red Sky Insurance Advisors and Ryan Olson provide no-cost, no-pressure Medicare guidance for people in Fitchburg, Madison, Dane County, and throughout Wisconsin. Reach out before an enrollment deadline passes to review your options, protect your coverage, and make a confident next step.