Senate Bill 21 (Laws 2026, Chapter 10) amends New Mexico's Medicare Supplement Act. The Legislature passed it in February 2026, Governor Michelle Lujan Grisham signed it in March 2026, and it takes effect on January 1, 2027. It gives people who already have a Medigap (Medicare Supplement) policy a yearly chance to change policies without being turned down or charged more because of their health.
Not in effect yet. Until January 1, 2027, switching Medigap plans in New Mexico usually means answering health questions (medical underwriting), unless you have a federal guaranteed-issue right, for example because your Medicare Advantage plan is leaving your area. The first birthday windows open in January 2027.
What SB 21 Does
- A yearly window: Your window opens on the first day of your birthday month and stays open for at least 60 days.
- Equal or lesser value: During the window you can buy any Medigap policy offered in New Mexico that is of equal or lesser value than the policy you have now, from your current insurer or a different one.
- No health questions: The insurer must issue the policy. It cannot deny, delay or condition coverage, or charge you more, because of your health, claims, medical care or medical conditions.
- No new pre-existing condition exclusions: The new policy cannot exclude conditions that your previous Medigap policy covered.
- Advance notice: Your current insurer must tell you 30 to 60 days before your window opens: the dates, your rights under SB 21, and any changes to your policy or premium.
Who Qualifies
You can use the birthday window if you have Medicare Part A or Part B, are 65 or older, and are covered by a Medigap policy. SB 21 does not help you buy Medigap for the first time. If you have Original Medicare without Medigap, or a Medicare Advantage plan, you still need your one-time Medigap Open Enrollment Period or a federal guaranteed-issue right to buy Medigap without health questions. People under 65 are not covered by SB 21.
How New Mexico Compares
| Feature | Federal rules (every state) | New Mexico, starting 2027 |
|---|---|---|
| One-time Medigap Open Enrollment | 6 months, starting when you are 65+ and enrolled in Part B | Same |
| Yearly switch without health questions | No | Yes, in a window of at least 60 days from the first day of your birthday month, if you already have Medigap |
| Which plans | Not applicable | Equal or lesser value than your current policy |
| Pre-existing condition exclusions after a switch | Can apply | Not for conditions your previous policy covered |
About a dozen other states, including California, Oregon, Idaho, Kentucky and Maryland, have similar birthday or anniversary rules, according to the state Aging and Long-Term Services Department's analysis of the bill.
Which Medigap Plans Can You Switch To?
The law lets you move to a policy of equal or lesser value than the one you have; the state's bill analysis describes this as a plan of “equal or lesser benefit level.” You cannot use the birthday window to move up to a plan with more benefits. For example, if you have Plan G you could buy Plan G from a different insurer, or a plan with fewer benefits such as Plan N:
- Plan G: The most comprehensive plan available to those newly eligible (covers everything except the Part B deductible of $283 in 2026)
- Plan N: A lower-premium option with small copays for office visits ($20) and ER visits ($50 if not admitted)
See the full Medigap plan comparison chart.
How to Get Ready for Your Birthday Window
- Watch for your insurer's notice 30 to 60 days before your birthday month, starting with January 2027 birthdays
- Compare premiums for your plan letter, and for plans with fewer benefits, from other insurers before your window opens
- Talk with a licensed insurance agent who can show you quotes from several companies in New Mexico
- Call NM SHIP at 1-800-432-2080 for free, unbiased counseling about your Medigap options
- Contact the NM Office of Superintendent of Insurance at 1-855-427-5674 with regulatory questions
Sources: Senate Bill 21 as enacted (New Mexico Legislature); Aging and Long-Term Services Department bill analysis.
Frequently Asked Questions
What does Senate Bill 21 do?
Starting January 1, 2027, it gives New Mexicans age 65 and older who already have a Medigap policy a yearly window to switch to a Medigap plan of equal or lesser value without health questions. Insurers must issue the policy and cannot charge more based on health.
Can I use SB 21 to switch Medigap plans now?
No. SB 21 takes effect on January 1, 2027. Before then, switching usually means medical underwriting unless you have a federal guaranteed-issue right.
When is my SB 21 window?
It opens on the first day of your birthday month and stays open for at least 60 days. Your insurer must notify you 30 to 60 days before it opens.
Can I use SB 21 if I have Medicare Advantage or no Medigap policy?
No. SB 21 applies only to people who are already covered by a Medigap policy. To buy Medigap without health questions otherwise, you need your one-time Medigap Open Enrollment Period or a federal guaranteed-issue right.
Does SB 21 apply to people under 65 with Medicare?
No. SB 21 applies to Medigap policyholders age 65 and older.
Compare Medigap Rates in New Mexico
When your birthday window opens, compare rates from several insurers. A licensed insurance agent can run quotes across the companies that sell Medigap in your area.