Turning 65 in Anthem, AZ: your 2026 Medicare enrollment timeline

Your window opens three months before the month you turn 65, and it closes three months after. That is seven months in total, it is keyed to your own birthday rather than to any date in the news, and nothing about living in Anthem changes it. If you are already drawing Social Security, Parts A and B arrive on their own. If you are not, nobody enrolls you — you do it yourself, and the clock is already running.

The rest of this is the month-by-month version, the 2026 numbers, and the two or three places people in the north Valley actually get caught out.

When exactly does my enrollment window open and close?

Medicare calls it your Initial Enrollment Period, and it is seven months long:

• the three months before the month of your 65th birthday
• your birthday month
• the three months after

So if you turn 65 in November 2026, your window runs August 1 through February 28. Enroll in one of those first three months and coverage starts on the first of your birthday month. Wait until your birthday month or later and coverage starts the first of the month after you enroll — which is the single most common reason someone ends up with a gap they did not plan on.

One local wrinkle worth knowing: if your birthday is on the first of the month, Medicare treats you as turning 65 the previous month, and your whole window shifts a month earlier. It catches people every year.

Source: Medicare.gov, "Get started with Medicare — when to sign up". Timeline is federal and applies identically in Maricopa County.

What does Medicare actually cost in 2026?

Here is the part everyone wants first, and it is the part that is genuinely simple — these are set by CMS and they are the same in Anthem as in Anchorage.

Two honest caveats about that premium. First, most people pay it, but higher earners pay more through IRMAA — a surcharge based on your tax return from two years back, so your 2026 premium is set by your 2024 income. It starts above $109,000 for a single filer and $218,000 for a couple filing jointly. You can check where you land in about a minute.

Second, Part A is premium-free only if you have 40 quarters of Medicare-covered work — about ten years. Below that there is a reduced rate and a full rate, and it is worth checking your quarters rather than assuming.

What happens if I am still working at 65?

This is the question I get most often from people out here, and the answer genuinely depends on one number: how many employees your employer has.

20 or more employees. Your group plan usually stays primary, and you can generally delay Part B without penalty. When you do retire, you get an eight-month Special Enrollment Period to pick it up. Many people still take Part A at 65 because it is premium-free — but not if you are contributing to a Health Savings Account, because enrolling in any part of Medicare ends HSA contributions.

Fewer than 20 employees. Medicare generally becomes primary at 65 whether you enroll or not. Delay Part B here and your group plan may pay as though Medicare had already paid its share — leaving you holding a bill nobody warned you about.

Retiree coverage, COBRA and any individual policy you buy on your own are not the same as active employer coverage for this purpose, and none of them protect you from the Part B penalty. If somebody tells you otherwise, get it in writing.

What do I choose after Part A and Part B?

Original Medicare on its own leaves you exposed: 20% coinsurance with no annual cap, and no drug coverage at all. So everyone puts something on top. There are two routes, and they are genuinely different bets:

• Medicare Advantage — one plan replaces the way your Medicare is administered, usually bundles drug coverage, often costs little or nothing per month, and holds you to a network with an out-of-pocket maximum.
• Medicare Supplement plus a Part D plan — you keep Original Medicare, the supplement pays most of what it does not, and you can see any provider who takes Medicare anywhere in the country. It costs more each month and buys more predictability.

The timing detail that matters more than the comparison itself: your Medigap Open Enrollment is six months long, starts the month your Part B begins, and during it no carrier can turn you down or price you up for your health history. After it closes, in Arizona, they can. If a supplement is even a maybe for you, that window is the one to think hard inside of — not later.

If you want to narrow it down before talking to anyone, the plan type finder asks six questions and points you at one of the two routes.

What if I miss my window?

Then you are looking at the General Enrollment Period, January 1 to March 31, with coverage starting the month after you enroll — and likely a Part B late-enrollment penalty of 10% of the standard premium for each full 12 months you could have had Part B and did not. It is added to your premium for as long as you have Part B. There is a Part D penalty too, calculated per month.

Special Enrollment Periods exist for genuine situations — losing employer coverage, moving out of a plan’s service area, and others — and they are the usual way out of a missed deadline. What counts as a qualifying event is narrower than most people assume, so it is worth reading rather than hoping.

What should I do right now?

If your 65th birthday is within the next six months, three things, in order:

1. Write down your prescriptions with dosages, your pharmacy, and the doctors you will not give up. Every useful comparison starts here and none can be done without it.
2. Work out whether you are enrolling or delaying, using the employee-count rule above. If you are delaying, get your employer’s confirmation of creditable coverage in writing now, not at retirement.
3. Put your window’s start date on a calendar — the first of the month three months before your birthday month. Then run the enrollment timeline tool to see your own dates rather than the generic ones.

And if any of that is ambiguous in your case — which it often is, particularly around employer coverage and HSAs — that is a short phone call rather than an afternoon of reading. Call (602) 844-6002 and we will get your dates straight. It costs nothing, and if the answer is “you are already doing the right thing”, that is what you will hear.