Medicare Plans and Enrollment Help

The two paths, side by side

Both work with Medicare. They handle your costs, your doctors, and your future options in almost opposite ways.

Medicare Advantage changes how you receive your Medicare benefits. A private plan approved by Medicare takes over administering your Part A and Part B coverage, usually bundles in prescription drug coverage, and often adds routine dental, vision, or hearing benefits. You keep paying your Part B premium, and the plan's own premium is frequently low or nothing at all. In exchange you work inside a provider network and follow the plan's rules on referrals and prior authorisation.

A Medicare Supplement, or Medigap, does the opposite. You stay in Original Medicare and keep the ability to see any provider in the country who accepts it. The Medigap policy then pays much of what Original Medicare leaves behind. You pay a higher monthly premium for that, and you buy a separate Part D plan for your prescriptions.

The enrollment windows that matter

Medicare runs on several separate calendars, and they do different things. Missing the wrong one is expensive and sometimes permanent.

• Initial Enrollment PeriodSeven months around your 65th birthday: the three months before, your birth month, and the three months after. This is when you sign up for Parts A and B. Different rules apply if you are still working and covered by an employer plan, and getting that wrong can mean a late enrollment penalty that never goes away.
• Annual Enrollment Period, October 15 to December 7Every year. You can join, switch, or drop a Medicare Advantage or Part D plan, with coverage starting January 1. This is the window most people mean when they say open enrollment.
• Medicare Advantage Open Enrollment, January 1 to March 31If you are already in a Medicare Advantage plan, you get one chance to switch to a different one or return to Original Medicare. It does not let you join Advantage from Original Medicare, and returning to Original Medicare here does not guarantee you a Medigap policy.
• Your Medigap open enrollment windowSix months, beginning the first month you are both 65 or older and enrolled in Part B. Once per lifetime. During it you can buy any Medigap policy sold in your state at the standard rate regardless of your health. This is the single most consequential window in Medicare, and most people spend it without knowing it is open.

Why the first choice deserves more thought than the price tag

You can move between Medicare Advantage plans every autumn for the rest of your life, and your health never enters into it. Medigap does not work that way. After your six-month window closes, insurers in most states can ask about your health history, charge you more because of it, or decline you outright.

That asymmetry is the whole game. Choosing Advantage at 65 is easy to do and, in most states, hard to fully undo years later when your health has changed and a Medigap policy has become the thing you want.

What happens if you try to switch to Medigap later

Part D is its own decision

Prescription drug plans are priced on far more than the monthly premium. Each plan publishes a formulary listing which drugs it covers and at which tier, and a network of preferred pharmacies where your cost is lower. The same prescription can cost very differently across two plans with nearly identical premiums.

Part D now includes an annual cap on what you pay out of pocket for covered drugs, which is set by Medicare and adjusted each year. It changed the maths considerably for anyone on expensive medication, and it is worth having someone run your actual drug list rather than comparing premiums.

If you go without creditable drug coverage when you first become eligible, a late enrollment penalty is added to your premium and it continues for as long as you have Part D. That is true even if you take nothing today.