Medicare 2026

Approaching 65 in Chesterfield? Here's Your 7-Month Medicare Window

CHESTERFIELD, Mo. — If a 65th birthday is on your horizon, Medicare is about to become one of the more important decisions on your to-do list. The good news: you have a set window to sign up, and knowing how it works can save you stress — and paperwork — later.

Chesterfield is in St. Louis County, and while plan choices are decided at the county level, the rules for signing up are the same across the country. Here's what to know before your birthday month arrives.

What the Initial Enrollment Period actually is

Your Initial Enrollment Period, or IEP, is the 7-month stretch built around your 65th birthday. It includes the three months before your birthday month, the month itself, and the three months after. This is when most people first sign up for Medicare Part A (hospital) and Part B (medical).

If you enroll in the three months before your birthday month, your coverage generally starts the first day of your birthday month. Wait until later in the window, and coverage starts the month after you sign up. Simple planning here prevents an uncovered gap.

Do you need to act, or are you enrolled automatically?

If you're already receiving Social Security benefits before 65, you're usually enrolled in Parts A and B automatically. Your red, white, and blue Medicare card should arrive in the mail about three months before your birthday.

If you're not yet drawing Social Security — which is common for people still working — you need to sign up yourself through the Social Security Administration. You can do this online at ssa.gov, by phone, or at a local office.

Still working at 65? Here's the wrinkle

Many Chesterfield residents keep working past 65 and stay on an employer health plan. If your employer has 20 or more employees, you can often delay Part B without penalty and enroll later through a Special Enrollment Period.

But smaller employer plans, retiree coverage, and COBRA don't always count as "creditable coverage" for delaying Medicare. Before you skip Part B, confirm in writing with your benefits administrator. Getting this wrong can trigger a Part B late-enrollment penalty that lasts as long as you have Medicare.

The parts, briefly

• Part A covers inpatient hospital care. Most people pay no premium because they paid Medicare taxes while working.
• Part B covers doctor visits, outpatient care, and preventive services. It has a monthly premium.
• Part C (Medicare Advantage) is an alternative to Original Medicare, offered by private insurers approved by Medicare.
• Part D covers prescription drugs. Out-of-pocket drug spending is capped at $2,100 in 2026 and $2,400 in 2027, and the maximum deductible is $615 in 2026 and $700 in 2027. The old "donut hole" no longer exists — Part D now has three phases. An optional Medicare Prescription Payment Plan lets you spread drug costs across the year.

Higher-income enrollees pay an added surcharge called IRMAA on Parts B and D. For 2026, IRMAA begins above $109,000 in income for a single filer.

Dates to keep on your calendar

Your IEP is your first shot, but Medicare also has yearly windows:

• Annual Enrollment Period: October 15 – December 7, when anyone with Medicare can change Part D or Medicare Advantage coverage.
• Medicare Advantage Open Enrollment: January 1 – March 31, for people already in a Medicare Advantage plan who want to switch or return to Original Medicare.

Where to get unbiased help

Missouri has a free State Health Insurance Assistance Program (SHIP) called CLAIM, staffed by trained counselors who don't sell insurance. You can also compare plan options in St. Louis County using the Plan Finder at medicare.gov, or call 1-800-MEDICARE (1-800-633-4227), available 24/7.