Part B Late Enrollment Penalty
The Medicare Part B late enrollment penalty is permanent and calculated as 10% for every 12-month period you were eligible for Part B but didn't enroll.
Example: If you delay Part B enrollment for 2 years (24 months), your Part B premium increases by 20% — permanently. On a $185/month standard premium, that's an extra $37/month for as long as you have Medicare. Over 20 years, that's $8,880 in extra premiums.
The penalty is waived if you had creditable coverage through an employer or union health plan during the delay.
Part D Late Enrollment Penalty
The Part D (prescription drug) late enrollment penalty is 1% of the national base beneficiary premium for each full month you went without creditable drug coverage after becoming eligible.
Example: Delay Part D enrollment for 14 months → permanent 14% penalty on your base drug premium. In 2026, the base premium is approximately $36.78, so a 14% penalty = ~$5.15/month added permanently.
Unlike the Part B penalty, the Part D penalty is recalculated annually as the base premium changes — so it can grow over time. Enroll in Part D during your Initial Enrollment Period, even if you take few medications.
How to Avoid Both Penalties
The simplest approach: enroll in Medicare Parts A, B, and D during your Initial Enrollment Period — the 7-month window around your 65th birthday (3 months before through 3 months after).
Exceptions — you can delay without penalty if:
- You're covered by creditable employer or union health insurance through active employment (your own job or a working spouse's job)
- You qualify for a Special Enrollment Period based on your employment situation
Retiree coverage is NOT the same as active employment coverage. If you're retired and on COBRA or retiree insurance, you generally cannot delay Part B or Part D without penalty.
Medigap and Late Enrollment
Medigap itself doesn't have a government late enrollment penalty, but there is a critical window: your 6-month Medigap Open Enrollment Period. During this window, insurers must offer you any Medigap plan with no medical underwriting.
After this window closes, Florida Medigap insurers can (and do) require medical underwriting — meaning they can charge higher premiums, exclude pre-existing conditions, or deny coverage entirely based on your health history.
Missing your Medigap window doesn't have a penalty, but it may permanently limit your options. Enroll during your initial eligibility period to lock in guaranteed acceptance.