Most people assume Medicare planning means choosing between plans, and that it happens somewhere around their sixty-fifth birthday. The plan choice matters, but it is rarely what causes problems.
What causes problems is timing. Several Medicare decisions carry consequences that last the rest of your life, and a few of them have to be made months before you turn 65.
The Window Is Seven Months
Your Initial Enrollment Period runs for seven months: the three months before the month you turn 65, your birthday month itself, and the three months after.
When you enroll inside that window determines when coverage starts. Enrolling in the three months beforehand generally means coverage begins the first day of your birthday month. Waiting until your birthday month or later pushes the start date back, which can leave a gap between one form of coverage ending and Medicare beginning.
This is worth knowing a year ahead rather than a month ahead, because the useful part of the window opens before most people start thinking about it.
If You Are Still Working
Plenty of people work past 65, and whether that changes anything depends almost entirely on one number: how many employees your employer has.
If your employer has 20 or more employees, the group health plan generally remains primary. You may be able to delay Part B without penalty and enroll later through a Special Enrollment Period.
If your employer has fewer than 20 employees, Medicare generally becomes the primary payer at 65. In that situation, not enrolling in Part B can mean your employer plan pays as secondary on claims Medicare would have covered — which in practice can leave you responsible for a great deal more than you expect.
This distinction catches people out regularly, and small employers are exactly where it bites. If you work for a company of this size, confirm the position with your HR contact and your plan documents well before your birthday.
The HSA Rule That Surprises People
If you contribute to a Health Savings Account, this one deserves attention.
Once you enroll in Medicare, you can no longer contribute to an HSA. The complication is that Part A coverage can be applied retroactively — up to six months back, though not before your 65th birthday — when you enroll after your Initial Enrollment Period has begun.
The practical consequence is that contributions made during those retroactive months may be treated as excess and carry a tax consequence. People planning to enroll after 65 commonly stop HSA contributions roughly six months in advance for this reason.
Your tax advisor should confirm how this applies to your situation. It is a genuinely technical area.
Penalties That Do Not Go Away
The Part B late enrollment penalty adds to your premium for every twelve-month period you could have enrolled and did not, and once it attaches it generally stays for as long as you have Part B. It is not a one-time charge.
Part D works on a similar principle. If you go without drug coverage that is at least as good as Part D — what Medicare calls creditable coverage — a penalty accumulates for that time.
Both are avoidable. Both are avoided by knowing the dates.
What COBRA and Retiree Coverage Do Not Do
Here is the most expensive misunderstanding in this whole subject. COBRA and retiree coverage generally do not count as active employer coverage for purposes of delaying Part B without penalty.
People retire, take COBRA, feel reasonably covered, and discover later that the clock on their Part B penalty was running the entire time. If you are approaching 65 and considering COBRA, check this specific point before deciding.
A Familiar Scenario
Someone working for a twelve-person company turns 65, likes their group plan, and sees no reason to change anything. Two years later a hospital claim reveals that Medicare should have been paying first. The employer plan pays only what it would have paid as secondary, and there is a substantial balance nobody planned for.
Nothing was done wrong on purpose. The employer size rule was simply never mentioned to anyone.
We’re Here To Help!
If you are within a couple of years of 65 — or still working and unsure whether that changes anything — the timing is worth working out early, while all the options are still open. Ask us and we will walk through the dates with you.
This article is general information about Medicare eligibility and enrollment timing. It is not tax advice, and HSA questions should be confirmed with your tax advisor. Rules and amounts are set by Medicare and are subject to change; confirm current details at Medicare.gov or 1-800-MEDICARE.
We do not offer every plan available in your area. Currently we represent 7 organizations which offer 35 products in your area. Please contact Medicare.gov, 1-800-MEDICARE, or your local State Health Insurance Program (SHIP) to get information on all of your options.