Medicare 2026

Medicare late penalties: how Part B and D add up

# Medicare late-enrollment penalties: how they work and how to avoid…

VISTA, Calif. — Missing a Medicare deadline can cost you every month for the rest of your life. That's the part of the program that trips up the most people, and it's the part that's easiest to prevent once you know the rules.

If you're turning 65 in Vista, or you're already retired and thinking about dropping employer coverage, the enrollment calendar matters just as much as the plan you eventually pick. Vista is in San Diego County, where dozens of Medicare Advantage and Part D options are sold — but none of that matters if a late-enrollment penalty is quietly added to your bill.

How the Part B penalty works

Part B covers doctor visits, outpatient care and many preventive services. If you don't sign up when you're first eligible — and you don't have other coverage that counts — Medicare adds 10% to your monthly Part B premium for each full 12-month period you were eligible but not enrolled.

That surcharge isn't a one-time fee. In most cases, you'll pay it every month for as long as you have Part B. Someone who waits three years to enroll could pay 30% more than their neighbor, month after month, for the same coverage.

How the Part D penalty works

Part D is prescription drug coverage. The penalty here works differently: it's 1% of the "national base beneficiary premium" for every month you went without Part D or other creditable drug coverage after your Initial Enrollment Period ended.

Medicare rounds it to the nearest 10 cents and adds it to your Part D premium each month. It sounds small at first, but skipping drug coverage for two or three years can add up quickly — and, again, the penalty typically sticks with you for as long as you have Part D.

"Creditable" is the key word. If your employer or union drug plan is at least as good as standard Part D, it counts, and you won't be penalized for staying on it. Your plan should send you a creditable coverage notice each year; hold onto it.

The deadlines that keep you safe

There are three enrollment windows worth memorizing:

• Initial Enrollment Period (IEP): The seven-month window around your 65th birthday — three months before, your birthday month, and three months after. This is the cleanest way to avoid both penalties.
• Special Enrollment Period (SEP): If you delayed Part B or Part D because you had job-based coverage, you generally get eight months to sign up for Part B and about two months for Part D after that coverage ends. Use it, or the penalty clock starts.
• General Enrollment Period: January 1 – March 31 each year, for people who missed their other windows. Coverage starts the month after you enroll — but any penalty owed still applies.

The Annual Enrollment Period (October 15 – December 7) and Medicare Advantage Open Enrollment (January 1 – March 31) are for changing plans, not for first-time sign-ups. Don't confuse them.

Common ways people get tripped up

A few situations cause most of the late-enrollment penalties we see:

• Retiree or COBRA coverage. These usually do NOT count as active employer coverage for Part B purposes. Many people learn this the hard way after leaving a job.
• Small-employer plans. If your employer has fewer than 20 workers, Medicare is typically the primary payer at 65, and staying only on the group plan can create a gap.
• Skipping Part D because you don't take medications. Even if your prescription list is empty today, going without creditable drug coverage starts the penalty clock. A low-cost drug plan is often the cheaper long-term move.
• Assuming Social Security handles it. If you're already drawing Social Security, you're auto-enrolled in Parts A and B. If you're not, you have to sign up yourself.

What to do for 2027

A few practical steps for readers in Vista and across San Diego County:

1. Mark your Initial Enrollment Period on the calendar as soon as you know your Medicare eligibility date. 2. If you're working past 65, ask your HR department in writing whether your health and drug coverage is creditable, and save the answer. 3. When employer coverage ends, treat the eight-month Part B SEP as a hard deadline, not a suggestion. 4. If you already have a penalty and believe it's a mistake — for example, you had creditable coverage the whole time — you can request a reconsideration through your plan or Medicare.

For 2026, keep the broader numbers in mind too: Part D has a $2,100 out-of-pocket cap, a maximum deductible of $615, and the old "donut hole" is gone. The Medicare Prescription Payment Plan lets you spread drug costs across the year. Higher-income beneficiaries (above $109,000 for a single filer in 2026) pay IRMAA surcharges on top of standard premiums — but IRMAA is separate from late-enrollment penalties.

Where to get personal help

Medicare rules are national, but your situation is personal. For free, unbiased help:

• Medicare.gov for enrollment periods, plan comparisons and creditable coverage rules.
• 1-800-MEDICARE (1-800-633-4227), 24/7.
• California's SHIP program, known here as HICAP (Health Insurance Counseling and Advocacy Program), which offers free one-on-one counseling to San Diego County residents.