Medicare 2026

Medicare Late Penalties: How Part B and Part D Fees Work

LAS VEGAS, Nev. — For people turning 65 in the Las Vegas area, the calendar matters more than almost anything else in Medicare. Miss the wrong window, and you can be stuck paying a late-enrollment penalty on Part B or Part D — often for as long as you have that coverage. The good news: the deadlines are fixed, they are public, and once you know how the dates line up, they are not hard to hit.

Las Vegas is in Clark County, where Medicare enrollment rules follow the same federal timeline as the rest of the country. Here is how the timing works this fall, and what happens if a key date slips by.

The one window that shapes everything: your IEP

Your Initial Enrollment Period (IEP) is the seven-month stretch built around your 65th birthday. It starts three months before the month you turn 65, includes your birthday month, and runs for three months after. For most people, this is when they should sign up for Part A, Part B, and — if they want drug coverage — a Part D plan.

If you sign up during the three months before your birthday month, coverage generally starts the month you turn 65. Sign up later in the window, and coverage begins the month after you enroll. That lag matters if you are trying to line Medicare up with the end of an employer plan.

What happens if you miss your IEP

If you don't enroll during your IEP and you don't qualify for a Special Enrollment Period (more on that below), you may have to wait for the General Enrollment Period, which runs Jan. 1 – March 31 each year. Coverage then begins the month after you sign up.

Two things can go wrong here:

• A gap in coverage. You could be without Part B or drug coverage for months.
• A penalty that follows you. Both Part B and Part D charge a late-enrollment penalty based on how long you went without coverage you were supposed to have.

How the Part B penalty is calculated

The Part B late-enrollment penalty is 10% of the standard Part B premium for each full 12-month period you were eligible but didn't sign up. It is added to your monthly Part B premium, and in most cases you pay it for as long as you have Part B.

So a person who waited two full years past their IEP without qualifying coverage would generally owe an extra 20% on top of the standard Part B premium — every month, going forward.

How the Part D penalty is calculated

The Part D late-enrollment penalty works a little differently. If you go 63 days or more in a row without "creditable" prescription drug coverage after your IEP ends, Medicare adds 1% of the national base beneficiary premium for every month you went without it.

That amount is rounded, added to your Part D premium, and typically stays with you as long as you have Part D. "Creditable" simply means drug coverage that Medicare considers at least as good as a standard Part D plan — often from an employer, union, or the VA. If you have that kind of coverage, keep the annual notice your plan sends you; it is the proof that you weren't uncovered.

Special Enrollment Periods — the built-in safety valve

Not everyone signs up at 65, and Medicare knows that. If you or your spouse are still working and covered by a qualifying employer group health plan, you generally get a Special Enrollment Period (SEP) to sign up for Part B without a penalty — usually up to 8 months after that employment or coverage ends, whichever comes first.

There is a similar rule for Part D: losing creditable drug coverage typically opens a 63-day window to enroll in a Part D plan penalty-free.

The trap people fall into is assuming COBRA or retiree coverage counts the same way active employer coverage does. For Part B, it usually does not. If you are moving from an employer plan to retirement in the Las Vegas area, it is worth checking before you assume.

The other dates worth circling

Once you're on Medicare, two more windows shape your year:

• Annual Enrollment Period (Oct. 15 – Dec. 7): You can join, switch, or drop a Medicare Advantage or Part D plan. Changes take effect Jan. 1.
• Medicare Advantage Open Enrollment (Jan. 1 – March 31): If you're already in a Medicare Advantage plan, you can switch to another one or go back to Original Medicare (and pick up a Part D plan).

These windows don't erase a Part B or Part D penalty that has already started, but they are your chance to adjust coverage each year without waiting.

A quick 2027 context note

A few program-level numbers to keep in mind for 2026: Part D has a $2,100 annual out-of-pocket cap, the maximum Part D deductible is $615, and the old coverage gap ("donut hole") has been eliminated since 2025, leaving three payment phases. Higher-income enrollees — generally above $109,000 for a single filer in 2026 — pay IRMAA surcharges on Part B and Part D. There is also an optional Medicare Prescription Payment Plan that lets you spread drug costs across the year in monthly amounts.

None of those change the penalty rules, but they are the backdrop your enrollment decisions sit against.