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Not always — but delaying without the right kind of coverage costs extra for life. If you or a spouse have coverage from a current employer with 20 or more employees, you can usually wait and sign up later without a penalty. If the employer has fewer than 20 employees, or your coverage is COBRA, retiree or Marketplace coverage, Medicare generally expects you to take Part B in your first window, and waiting can leave bills unpaid and add a permanent surcharge.
Apply this to my situationThe rules behind this
Your first enrollment window lasts seven months
The Initial Enrollment Period starts three months before the month you turn 65, includes your birthday month, and ends three months after it. Signing up in the first three months usually means coverage starts the month you turn 65.
Who this is for
People becoming eligible for Medicare because they are turning 65.
What changes it
- If your birthday is on the first of the month, the whole window moves one month earlier.
- If you have coverage from current work, you may be able to enroll later without a penalty.
The question that settles it
“What are my exact Part A and Part B enrollment dates?” — Social Security, 1-800-772-1213.
Signing up late for Part B usually costs extra for life
If you sign up for Part B after your first window ends and did not have coverage from current work in between, Medicare generally adds 10% to your Part B premium for every full 12 months you could have had Part B but did not — and the extra amount usually lasts as long as you have Part B.
Who this is for
People who delay Part B without qualifying job-based coverage.
What changes it
- Coverage from your own or a spouse’s current employer generally lets you delay without a penalty.
- COBRA and retiree coverage usually do not count as current-employment coverage.
The question that settles it
“Will I owe a Part B late-enrollment penalty, and how is it calculated for me?” — Social Security.
Employer size decides who pays first — and whether delaying Part B is safe
If the employer has 20 or more employees, the job plan usually pays first and Medicare second — so many people safely delay Part B. If the employer has fewer than 20 employees, Medicare usually pays first, and a job plan may pay very little until you have Part B. In that case delaying Part B can leave large bills unpaid.
Who this is for
People 65+ with coverage from their own or a spouse’s current employer.
What changes it
- The count is the employer’s total employees, not the number on the plan.
- Different rules apply for disability-based Medicare (the threshold is 100 employees).
The question that settles it
“How many employees does the company have in total, and does our plan pay first or second for someone 65 or older?” — your benefits administrator, in writing.
Get help
Free Medicare counseling
California HICAP offers free, confidential Medicare counseling. Ask the local program about language and appointment availability.
California HICAP1-800-MEDICARE
Call 1-800-MEDICARE and ask for an interpreter. TTY: 1-877-486-2048.
Call Medicare · 1-800-633-4227Official information in other languages ↗External resource. Some pages are in English; ask for language assistance if needed.