Getting started
Turning 65 in St. Louis, MO
Your 65th birthday starts a countdown, whether you've lived in Affton your whole life or just moved to St. Charles to be near the grandkids. Medicare gives you seven months to sign up: the three months before your birthday month, the month itself and the three months after.
Apply during the three months before your birthday month and your coverage starts on the first of that month. Wait longer and your start date moves back. That's why it pays to start planning around 64 and a half, not the week of your birthday.
- A seven-month window built around your birthday
- Different rules if you're still working
- One guaranteed shot at a Medigap plan
- Free, local, no-pressure help
Your dates
Turning 65 enrollment calculator
Find your Medicare enrollment window
Enter your date of birth to see your Initial Enrollment Period, the month to apply, when coverage could start and what to check if you're still working. Our team can go over the timeline with you from there.
Your Medicare enrollment timeline
- Initial Enrollment Period
- Month to apply
- Coverage could begin
- You turn 65
Check your employer coverage first
Still working, or covered by a spouse's employer plan? If that employer has 20 or more employees, you can usually delay Part B without a penalty. Under 20 employees, Medicare typically pays first at 65, and waiting can leave you underinsured. An HSA contribution changes the math again. Check with HR before you decide, or ask a licensed agent to walk through it with you.
Next step:
This is an estimate based on standard Medicare rules and your date of birth. It is not an official determination. Confirm your dates with Social Security or Medicare.gov.
Timeline
What to do, and when
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1
3 to 6 months before your birthday
Decide whether to start Part B now or wait because you still have coverage through a job. Start writing down your doctors and prescriptions.
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2
3 months before
Sign up for Part A and Part B through Social Security if you haven't yet. If you already get benefits, your card arrives on its own.
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3
2 months before
Choose your path: Original Medicare with Medigap and Part D, or a Medicare Advantage plan. Check which plans include your doctors, whether you see them at BJC, Mercy, SSM Health or St. Luke's.
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4
1 month before
Send in your applications so your cards arrive before coverage begins. Make sure your old coverage doesn't end before the new one starts.
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5
After your birthday
Your six-month Medigap window opens when Part B starts. Use it. It's the one time your health history can't change your price.
Still working?
A job-based plan changes the timeline
If you or your spouse still work and the group plan covers 20 or more employees, you can usually put off Part B without a penalty and keep that coverage. Most people still take Part A, since it's usually free. The exception is if you put money into an HSA: enrolling in any part of Medicare stops those contributions.
When the job ends, you get eight months to sign up for Part B. COBRA and retiree coverage don't stretch that window, whatever the paperwork seems to say. Getting this wrong is one of the costliest Medicare mistakes. You can check the math with our Part B penalty calculator.
Small employers follow different rules
If your employer has fewer than 20 workers, Medicare usually becomes your main coverage at 65, and waiting on Part B can leave you with gaps. Talk to HR before you decide.
Choosing
Two paths, one choice
- Original Medicare with Medigap and Part D: almost any doctor who takes Medicare, a higher premium, few surprises
- Medicare Advantage: a lower premium, a set network, copays as you go, often dental and vision
- Either way, you still pay your monthly Part B premium
- A licensed agent can price both for you at no cost
Read more about Medigap, Medicare Advantage and Part D drug plans, or begin with the Medicare checklist. If your first window passes, the Annual Open Enrollment period comes around every October 15 to December 7.
Close to home
Turning 65 around St. Louis
We help new enrollees in St. Louis City, St. Louis County and St. Charles County. Your doctors shape the choice. Care here is split among BJC (including Barnes-Jewish and Missouri Baptist), Mercy, SSM Health (including Saint Louis University Hospital) and the independent St. Luke's in Chesterfield, and Medicare Advantage networks don't always include all of them. The plans for sale can also differ between the city, the county and St. Charles County. Veterans who use the John Cochran or Jefferson Barracks VA medical centers should look at how VA care fits with Medicare before choosing. Find your area on our service areas page. For free counseling, Missouri SHIP takes calls at 800-390-3330.
Have your enrollment timeline checked
We'll confirm your dates, check whether your job coverage lets you wait on Part B, and go over both coverage paths with you. No cost, and no obligation to enroll.
What to expect
Free review- A licensed agent calls you back during business hours, Mon-Fri, 8:30am-5:30pm CT
- Your doctors and prescriptions get checked before any plan is suggested
- No fee for our help, and your premium is the same either way
- No obligation to enroll, and no pressure if you'd rather stay put
Reviewed by the licensed insurance agents at St. Louis Senior Insurance. Last reviewed: October 2026. Office hours: Mon-Fri, 8:30am-5:30pm CT.
Thanks, we have your request.
A licensed agent will call you during business hours, Mon-Fri, 8:30am-5:30pm CT. If you'd rather not wait, call 314-463-5815 now.
Common questions
Turning 65 questions in St. Louis
What is my Initial Enrollment Period?
Will Medicare sign me up on its own?
Can I hold off on Part B while I'm still working?
What does Part B cost in 2026?
When is my Medigap open enrollment?
Is there free Medicare counseling in Missouri?
Turning 65 this year?
We'll confirm your dates, check your doctors and price both paths. Free, with no obligation to enroll.