Missouri Medicare Enrollment Periods Explained (With Helpful Infographics)

There are different Medicare enrollment periods for different situations

  • Signing up for Medicare for the first time (usually at age 65)
  • Signing up for the first time if you didn’t sign up at age 65
  • Changing your plan
  • Cancelling your plan

There are also different enrollment dates if you are choosing, switching, or disenrolling from a Medicare Advantage or Medigap/Supplement plan. We’ll go through each Medicare enrollment period, and answer your questions about certain scenarios you may find yourself or a loved one in. It’s not as confusing as you might think!

Check this infographic for information on when you can enroll in Medicare in Missouri for the first time. You can also change yearly, but need to do so in the right enrollment period.

When to sign up for Medicare for the first time in Missouri

In most cases, you are eligible for Medicare when you turn 65. This first sign-up period is called your Initial Enrollment period. You should sign up during this Medicare Enrollment Period if you don’t have group health coverage from your employer with 20+ employees. Why? If you don’t purchase Medicare Part B and Part D when you are first eligible, you’ll pay a penalty for the rest of your life when you finally do sign up for Part B and Part D.

There are two timelines for enrolling in Medicare in Missouri for the first time- one for Original Medicare or Medicare Advantage, and the other for a Medigap (Supplement) plan

Initial Medicare Enrollment Period

This Initial Enrollment Period when most people enroll in Medicare at 65 is seven months long. You can enroll starting 3 months before your birthday month and ending 3 months after your birthday month.

For example, if your birthday is July 8, you have from April 1 to October 31.

When will my coverage start after my Initial Enrollment Period?

When does my Medicare insurance coverage start?

Just click the month you will enroll into Medicare to find out when your coverage will begin.

Your Medicare coverage will start 1 month after enrollment.

Your Medicare coverage will start 2 months after enrollment.

Your Medicare coverage will start 3 months after enrollment.

Your Medicare coverage will start 3 months after enrollment.

*If your birthday is on the first day of the month, your coverage will start the first day of the prior month.

Special Medicare Enrollment Period

Sometimes life happens, and you lose your health insurance- like when you move to a new state that isn’t covered or you lose your insurance through an employer. If these apply, you have the opportunity to sign up, change, or cancel your Medicare health or prescription plan.

The Special Enrollment Period is the two months after the qualifying event takes place, so act quickly. If you have questions about if yours is a qualifying event, we’ll be happy to get you answers.

If your event doesn’t qualify for a Special Enrollment Period, but you still need to add, change, or cancel coverage, you can do so in the General Enrollment Period, explained next.

You can change your Missouri Medicare plan every year, but you have to do it during the correct enrollment period. There's an Annual Enrollment Period, General Enrollment Period, and Medicare Advantage Open Enrollment Period.

General Enrollment Period

This enrollment period is for people who didn’t sign up when they turned 65, or otherwise became eligible later. It is at the beginning of every year from January 1 to March 31. When you sign up for a plan during the General Enrollment Period, your coverage will take effect on July 1.

Remember that it’s best to sign up during the Initial Enrollment Period if you can, because you can face financial penalties for the rest of your life.

When can I purchase a Medicare Supplement (Medigap) plan?

Many people choose Original Medicare, but buy a Medigap, or Supplemental, plan to lower their out-of-pocket costs. There’s a specific enrollment period for Supplemental coverage as well, called the Medicare Supplement Open Enrollment Period

Medigap (or Medicare Supplement) Open Enrollment Period

The Medigap Open Enrollment Period starts the month you turn 65 and lasts 6 months. You can’t enroll in a Supplemental plan without already being enrolled in Part B, so be sure to factor that into your timeline.

What we recommend to our clients is visiting us in their 65th birthday month so they can enroll in everything at once, even if they choose a Medigap plan.

Also, be aware that certain Medigap policies aren’t available to new enrollees (keep reading to find out which ones).

Are all Medigap Plans Available for Everyone?

Nope! After January 1, 2020, new enrollees cannot sign up for a certain type of plan. This newly-regulated plan is any Medigap/Supplement plan that pays your Part B deductible. It simply won’t be available for people enrolling after January 1, 2020.

Can You Sign up for a Medigap or Supplemental Plan in the Future?

You may be able to choose a Medigap plan later. See, when you choose a Medigap at 65, you cannot be denied for pre-existing conditions. If you decide you want a Medigap plan later on, the insurance company may charge you more or ask you pre-qualifying questions.

There are certain circumstances that allow you to get a Medigap plan after your Medigap Open Enrollment Period, called Guaranteed Issue Rights. We often help clients sign up for Medigap plans later in life, so we encourage you to set up a no-cost meeting to go over your options.

When can I change my Medicare plan during the year?

The Medicare Annual Enrollment Period is the time period when you can change your plan.

If you’re on Medicare Part A and Part B (Original Medicare) you can:

  • Enroll in a Part D prescription drug plan;
  • Change your Part D plan;
  • Disenroll from Part D (though it’s not recommended because you’ll owe a penalty later);
  • Switch to a Medicare Advantage Plan; or
  • Keep the same coverage by not taking any action.

There are lots of rules around changing and joining a Medicare Advantage plan, but the Annual Enrollment Period is the window when you’ll want to switch, cancel, or join a Medicare Advantage plan. You can also switch, cancel, or add a Part D plan during this time.

If you are enrolled in a Medicare Advantage plan you can:

  • Switch to Original Medicare;
  • Change Medicare Advantage plans- including adding or dropping Part D coverage and/or switching providers; or
  • Do nothing to stay in the same plan, unless your current plan is being altered by your insurer.

Keep reading for another enrollment period allowed for Medicare Advantage enrollees.

If you are eligible, but haven’t signed up yet, you can use the Annual Enrollment Period to get enrolled in the plan that fits you best.

When is the Annual Enrollment Period (also known as Open Enrollment)?

You can enroll in Medicare or change your Medicare plan at the end of every year from October 15 to December 7. Your coverage for the plans you choose will start Jan 1 of the following year.

Since the Annual Enrollment Period is the only time of the year most people can switch plans, we take advantage of it by doing cost-free Annual Reviews for our current and new clients. We make sure that there aren’t any plans that are a better fit for their needs. We can also switch plans based on changing health circumstances.

When can I change plans if I have Medicare Advantage?

Like we talked about above, the Annual Enrollment Period is a great time to switch, cancel, or get a Medicare Advantage plan. There is also an enrollment period specifically for Medicare Advantage that you can take advantage of as well. It’s called the Medicare Advantage Open Enrollment Period.

When is the Medicare Advantage Open Enrollment Period?

The Medicare Advantage Open Enrollment Period is every year from January 1 to March 31. During this time you can:
Switch to another Medicare Advantage plan- either from the same insurance company, or from a different one;
Switch to Original Medicare (Part A and Part B) alone or with a Medigap (Supplement) plan. Remember that you may be penalized for pre-existing conditions if you don’t get Medigap when you first become eligible.

When can I sign up for Medicare if I didn’t sign up at age 65?

You can use any of the following enrollment periods to sign up after your Initial Enrollment Period around your 65th birthday:
-Annual Enrollment Period (October 15 to December 7)
-Medicare Advantage Open Enrollment Period (January 1 to March 31)
-General Enrollment Period (January 1 to March 31)


Yes, we know that keeping track of which dates are important and which plan you have can be overwhelming, but that’s why we started this company. We offer personalized help in choosing a plan for each of our clients. It’s also why we call you for Annual Medicare Reviews every year! It’s just one way we put our clients first and make your life a little easier- all at absolutely no cost to you.

Fill out our contact form below and Angela will set up an appointment to answer your questions and connect you to the right Medicare plan.

Fill Out Your Basic Info to See Your Medicare Plan Options

Jeremy works with Medicare clients to answer questions, assist with enrollment, and run plan comparisons to find the right one for your needs.

He’s also an expert in Dual Enrollment for those on both Medicare and Medicaid.

Not sure whether to choose a Medicare Advantage or Medicare Supplement Plan?


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