If you are working past age 65 in New Mexico, your Medicare decisions are more complex than for those who retire at 65. New Mexico's federal and national-lab workforce—at Los Alamos National Laboratory, Sandia National Laboratories, Kirtland Air Force Base, and federal agencies—commonly works past 65, as do many private-sector New Mexicans who choose to keep working. The choices you make about Parts A, B, and D affect your taxes (especially HSA contributions), your healthcare costs, and your access to coverage for years to come. This guide explains exactly how to make Medicare decisions when you're still employed.
The Four Questions to Answer at 65
Most people assume they should sign up for every part of Medicare at 65. If you have health coverage from your own or your spouse's current job, the rules are different:
- Part A? It's premium-free for most people, but enrolling ends your ability to contribute to a Health Savings Account (HSA). If you already collect Social Security, Part A starts automatically at 65, and you can't turn it down without giving up your Social Security benefits.
- Part B? You can delay it without a penalty only while you have group health coverage based on your or your spouse's current employment. Your employer's size decides whether Medicare or the employer plan pays first.
- Part D? You can wait only if your employer's drug coverage is "creditable" (at least as good as standard Part D). Your employer sends a notice each year that says whether it is.
- Medigap? You get one 6-month Medigap Open Enrollment Period with guaranteed issue, and it starts only when you have Part B.
The Six Key Decisions for Working Past 65
HSA Contributions & Medicare
Critical 6-month Part A lookback rule. Enrolling in Medicare ends HSA contributions immediately, and you may owe tax on contributions made during the months your Part A coverage is retroactive.
Coordinating Employer Coverage
The 20-employee rule, the COBRA myth, and how Medicare coordinates with workplace insurance.
Part B Special Enrollment Period
You have an 8-month SEP after leaving employer coverage. Avoid permanent Part B penalties with Form CMS-L564.
Part D & Creditable Coverage
What "creditable" means, the 2-month SEP after losing creditable coverage, and how to avoid Part D penalties.
Spouse on Your Employer Plan
If your spouse is on your employer health plan, your Medicare decisions affect them too.
Retirement Timing: 66, 67, 68, 70
How your retirement age affects Medicare enrollment, Social Security, and overall benefit strategy.
A Quick Decision Framework
A simplified starting point. Your own plan's details matter, so confirm before you decide:
| Your Situation | Part A | Part B | Notes |
|---|---|---|---|
| Still working, contributing to an HSA | Delay | Delay | Any Medicare enrollment ends HSA contributions. Stop contributing 6 months before you enroll (Part A is backdated up to 6 months). |
| Still working, large employer (20+), no HSA | Yes | Optional | Employer plan pays first; premium-free Part A is usually harmless. |
| Still working, small employer (fewer than 20) | Yes | Yes | Medicare pays first, so the employer plan may pay only what Medicare wouldn't. |
| Covered through your spouse's current job | Yes (unless HSA) | Can delay | Same rules as your own job, based on the size of your spouse's employer. |
| Federal employee still working, with FEHB | Yes (unless HSA) | Can delay | Enroll within 8 months of retiring. FEHB as a retiree does not protect you from the Part B penalty. |
| COBRA after leaving a job | Yes | Yes | COBRA is not current-employment coverage and does not give you a Part B Special Enrollment Period. |
| Self-employed or Marketplace plan | Yes | Yes | Not coverage from a current job; enroll during your Initial Enrollment Period. |
Part D follows its own rule: you can wait as long as your drug coverage is creditable, and you have 2 months after it ends to join a Part D plan without a penalty.
Why Working Past 65 is Common in New Mexico
New Mexico has a large federal and defense workforce. Major employers—Los Alamos and Sandia national laboratories (run by contractors for DOE/NNSA), Kirtland Air Force Base, White Sands Missile Range, and federal agencies across Albuquerque, Santa Fe, and Las Cruces—mean thousands of New Mexicans face decisions about Medicare while still actively employed. Each group has its own coverage situation:
- Los Alamos and Sandia national laboratories: Lab employees work for the contractors that run the labs, so they generally have the contractors' group health plans, not FEHB. Ask HR how the lab's retiree coverage works with Medicare before you retire.
- Kirtland, Holloman, and Cannon Air Force Bases and White Sands Missile Range: Civilian federal employees have FEHB; military retirees and their spouses may have TRICARE, which becomes TRICARE For Life only if you have both Part A and Part B. Contractors on base have their employers' plans.
- State of New Mexico and public employers: Active employees have the state or employer group plan; retiree coverage through the New Mexico Retiree Health Care Authority (NMRHCA) has its own Medicare enrollment requirements, so check with NMRHCA before you retire.
The Federal Employee Health Benefits (FEHB) program creates unique considerations: while you are still working for the government you can delay Part B without penalty, but once you retire FEHB no longer protects you, so choosing whether to add Part B at 65 or at retirement requires careful analysis. See our full FEHB & Medicare guide.
The Most Common (and Costly) Mistakes
- Continuing HSA contributions after Medicare Part A starts. Part A enrollment retroactively starts up to 6 months before your application. Contributions during this lookback period create tax penalties.
- Assuming COBRA counts as employer coverage for Medicare. It does NOT. If you delay Part B because you have COBRA, you'll face permanent late penalties.
- Missing the 8-month Part B Special Enrollment Period. The 8 months start when your job or your employer coverage ends, whichever comes first. Past that, you pay 10% more for every full 12-month period you could have had Part B but didn't—permanently.
- Delaying Part B with coverage that isn't from a current job. Retiree plans, Marketplace plans, and VA health care don't let you delay Part B without a penalty.
- Missing the Medigap Open Enrollment window. After it closes, insurers in most cases can turn you down or charge more because of your health.
What About Medigap?
Your Medigap Open Enrollment Period is the 6 months that start when you are both enrolled in Part B and age 65 or older. Miss this window, and you could be denied Medigap coverage or charged much higher premiums based on your health.
That means if you delay Part B because of coverage from a current job, your Medigap Open Enrollment is also delayed—which is good news, not bad: the window opens when you actually need it. New Mexico residents also benefit from Senate Bill 21: starting in 2027, once you have a Medigap policy you can switch to a plan of equal or lesser value each year, in a window that opens in your birthday month, without health questions. Compare Medigap plans in New Mexico.
Free Help With Your Decision
Government help
- Medicare: 1-800-MEDICARE (1-800-633-4227), TTY 1-877-486-2048, or Medicare.gov
- Social Security (Part A and Part B enrollment, Form CMS-L564): 1-800-772-1213 or ssa.gov
Licensed insurance agents (Benefits Life)
- Benefits Life licensed insurance agents: 505-MEDICARE (505-633-4227), TTY 711
Get Personalized Working-Past-65 Guidance
Working-past-65 Medicare decisions are complex and depend on your specific employer, plan size, HSA status, and retirement timing. A licensed insurance agent in New Mexico can review your situation and help you avoid costly mistakes.