New Mexico · Medigap · Annual review

Can I Switch Medigap Plans When My Premium Goes Up? New Mexico 2027

The rate letter came and the number is bigger. Here is what federal law lets you do about it today, what New Mexico's new birthday rule adds on January 1, 2027, and how a Medigap policy gets reviewed each autumn.

By the New Mexico Medicare Help Data Desk

Reviewed by Brian Penner, Independent Medicare advisor — no pressure · Published October 3, 2026

Yes, you can switch Medigap plans when your premium goes up, and because every Plan G, Plan N or other lettered plan carries identical benefits at every company, moving to a cheaper company costs you nothing in coverage. The catch is acceptance. Medicare.gov is direct about it: "In most cases, you won't have a right under federal law to switch Medigap policies, unless" you are inside your 6-month Medigap Open Enrollment Period or have a guaranteed-issue right. At any other time the new company may use medical underwriting, which means health questions, and may decline you or charge more. That is why so many New Mexicans have stayed on a policy whose rate kept climbing. Starting January 1, 2027, Senate Bill 21 changes the answer: every year, for 60 days beginning on the first day of your birthday month, any Medigap policyholder 65 or older can move to a policy of equal or lesser value at any company selling in New Mexico, and the company "shall not deny, delay or condition the issuance ... or discriminate in the price of coverage" based on health. The 71,380 New Mexicans with a Medigap policy get that right for the first time in 2027.

Sources: Medicare.gov — Can I change my Medigap policy?; New Mexico Senate Bill 21 (2026), final text; NM Aging & Long-Term Services Department — Senate Bill 21 overview.

Why did my Medigap premium go up?

Because it was always going to. Medicare.gov's Medigap costs page ends with one flat sentence: "Premium amounts typically increase each year." The size of the increase depends on how the company priced the policy when you bought it, and CMS describes three methods. Which one you are on is printed in your policy and is worth finding before you shop.

Source: CMS — Choosing a Medigap Policy (Product 02110), "How do insurance companies set prices for Medigap policies?" CMS notes the examples "aren't actual costs." Medicare.gov — Get Medigap costs.

Two more things move a premium that have nothing to do with you: the company's claims experience across its whole block of New Mexico policies, and whether that block is still open to new buyers. The state's own analysis of Senate Bill 21 describes the pattern its counselors hear on the phone: "beneficiaries who have had a Medigap policy for many years and reach a point where the premium has increased so much that they can no longer afford to continue the coverage on their limited income." Until 2027, their options were to pay, to drop Medigap and carry Original Medicare's 20% with no cap, or to move to Medicare Advantage. The bill was written to add a fourth.

Source: NM Aging & Long-Term Services Department — Agency bill analysis, SB 21 (February 3, 2026).

Can I switch companies right now, before the birthday rule starts?

You can apply, and a company may well say yes. What you do not have, between now and January 1, 2027, is a right to be accepted unless one of the federal windows applies. Here is how each works.

Sources: Medicare.gov — When can I buy a Medigap policy?; Medicare.gov — Can I change my Medigap policy?; NM Senate Bill 21. The six-month period is shown as 180 days for scale.

• Your Medigap Open Enrollment Period. The 6 months that begin the first month you have Part B and are 65 or older. Medicare.gov: "Your Medigap Open Enrollment Period is a one-time enrollment. It doesn't repeat every year." If you are still inside it, you can switch to any policy at any company with no health questions.
• A guaranteed-issue right. Federal law lists specific situations: your Medicare Advantage plan is leaving Medicare or you move out of its area and you return to Original Medicare; your employer or union plan that pays after Medicare ends; your Medigap company goes bankrupt or misled you; and the two trial rights for people who tried Medicare Advantage within their first year. In each case you may buy Plan A, B, C, D, F or G (C and F only if you were eligible for Medicare before 2020), and you must apply "no more than 63 days after your coverage ends." A premium increase on a policy you still hold is not on the list. If your situation is a Medicare Advantage plan that is being discontinued for 2027, the full rules are in Medigap guaranteed-issue rights in New Mexico for 2027.
• Underwriting. Outside those windows, Medicare.gov says, "You can switch if an insurer is willing to sell you a new Medigap policy." The application will ask about your health, and the company may decline, or accept you at a higher rate. Many healthy applicants are accepted; the point of Senate Bill 21 is the ones who are not.

If you do switch, by any route, three federal protections apply. Keep the old policy until the new one is in hand: you have a "30-day free look period" on the new policy, and "you'll need to pay both premiums for the month that you have both." On the new application you will "promise that you'll cancel your first Medigap policy." And if you have held your current policy longer than 6 months and the new one has the same benefits, "the new insurance company can't exclude your pre-existing condition or make you wait before it covers it"; held under 6 months, you may face a wait of up to 6 months for conditions you already have.

Sources: Medicare.gov — When can I buy a Medigap policy?; Medicare.gov — Can I switch or drop my Medigap policy?; CMS — Choosing a Medigap Policy, pp. 17–18 and 26–27.

How does New Mexico's birthday rule work from January 1, 2027?

Senate Bill 21 adds a new section to the state Medicare Supplement Act. It was signed in March 2026 and takes effect January 1, 2027. The ALTSD analysis puts New Mexico alongside eleven other states, including California, Oregon, Nevada and Oklahoma, with a birthday or anniversary rule. This is what the statute itself says, not a summary of it.

Sources: New Mexico Senate Bill 21 (2026), final text, Sections 1–2; NM ALTSD — Governor signs Medigap bill into law (March 11, 2026); ALTSD agency bill analysis.

Notice what the rule does and does not do. It does not let you buy Medigap for the first time, and it does not let you buy more coverage than you have. It lets a person who has been paying a rising premium for years take the same lettered plan, or a leaner one, to a company whose price is lower, without a health question. That is exactly the situation the rate letter puts you in.

When is my first birthday window?

The first windows open on January 1, 2027 for January birthdays and roll through the year from there. The statute counts from the first day of your birthday month, not from your birthday, and requires "at least" 60 days; the notice your insurer sends will carry the exact closing date. The table shows the opening date and the sixtieth day for each month in 2027.

Source: NM Senate Bill 21, Section 2(A); day counts are ours, counting the opening day as day one. Your insurer's approved notice controls.

A practical consequence: a policy "generally" begins "the first of the month after you apply," so an application early in the window gives a clean handoff on the first of the following month, with the 30-day free look running on the new policy before you cancel the old one.

Source: Medicare.gov — How do I buy a Medigap policy?

What counts as "equal or lesser" coverage?

The statute uses the phrase "equal or lesser value" and leaves the comparison to the standardized benefit chart. Because the lettered plans nest inside one another, most moves are obvious.

Sources: NM Senate Bill 21, Section 2(A)(1); CMS — Choosing a Medigap Policy, benefit chart (pp. 6–7). Plan G and Plan N are compared line by line in Medigap Plan G vs. Plan N in New Mexico.

How do I compare Medigap premiums?

Simpler than comparing Medicare Advantage plans, because there is no network and no formulary. The doctors step and the drugs step of our usual order do not apply; a Medigap comparison is price, pricing method and company. CMS's shopping steps, lightly condensed:

1. Pick the letter first. Decide whether you are staying on your plan or stepping down, say from G to N. Compare "the same lettered plan offered by different insurance companies."
2. Get more than one quote at your current age. "Since costs can vary widely between companies, contact more than one company." Medicare.gov's Medigap policy finder lists every company selling each letter in your ZIP, with estimated prices; CMS says to "contact the insurance company for a more accurate price."
3. Ask how the policy is priced. CMS's own question list for insurers includes "Do you price this Medigap policy by using community-rating, issue-age-rating, or attained-age-rating?" and, for attained-age, "How frequently does the premium increase due to my age?"
4. Ask about the last three years. Also from CMS's list: "Has the premium for this Medigap policy increased in the last 3 years due to inflation or other reasons?" The lowest quote today from a company with a steep rate history may not be the lowest-cost policy in five years.
5. Ask about discounts. Medicare.gov notes discounts "for women, non-smokers, or married people," for paying yearly, and for automatic bank payment. Two spouses on the same company may each qualify for a household discount.
6. Check the company's record. "Contact your State Insurance Department to find out if they have any complaints against the insurance companies selling the plan you want." In New Mexico that is the Office of Superintendent of Insurance.
7. Then apply, keep the old policy through the free look, and get a receipt. "If you buy your policy from an agent, get a receipt with the insurance company's name, address, and phone number for your records."

Sources: Medicare.gov — How do I buy a Medigap policy?; CMS — Choosing a Medigap Policy, Steps 2–3 (pp. 21–22); Medicare.gov — Get Medigap costs. Free counseling: New Mexico's ADRC-SHIP, 1-800-432-2080, listed in Medicare & You 2027.

One rule of the road that matters more under a birthday rule than before: it is illegal for anyone to "pressure you to buy a Medigap policy or lie to get you to switch to a new company or policy," and an agent may sell you a new policy when you already have one only if "you state, in writing, that you plan to cancel your existing policy." A legitimate comparison ends with the numbers on paper and the decision left to you.

Source: CMS — Choosing a Medigap Policy, "Watch out for illegal practices" (p. 23).

Will the birthday rule push premiums up?

Nobody knows yet, and we will not pretend to. The argument for the rule, in ALTSD's words, is that it "supports more balanced Medicare Supplement risk pools by reducing the current dynamic where only healthy enrollees can switch plans." The argument against, heard in other states, is that letting people move after they get sick raises costs for the company that receives them. New Mexico's insurance regulator is measuring rather than guessing: in July 2026 the Office of Superintendent of Insurance issued a Medicare Supplement Data Call "to better understand the potential rate impacts in New Mexico," requiring every carrier to submit enrollment, claims, premium and rate-change data from 2022 onward, by pricing method, by October 21, 2026, along with the same data from comparable birthday-rule states. The results are confidential by statute, but the rate filings that follow are not. The practical point for a policyholder is unchanged either way: the rule gives you a yearly chance to re-price the same coverage, and the review is worth doing whether rates rise or fall.

Sources: NM ALTSD — Senate Bill 21 overview, "Promotes Market Stability"; NM Office of Superintendent of Insurance — 2026 Medicare Supplement Data Call (July 2026); KFF — Medigap Enrollment and Consumer Protections Vary Across States (2018), on rating systems and state protections.

What if I am in Medicare Advantage and want Medigap?

The birthday rule is not for you, because it applies only to people who already hold a Medigap policy. Your routes are the federal ones. If your Medicare Advantage plan is being discontinued for 2027, as Presbyterian's and CHRISTUS Health Plan's are in New Mexico, you have a guaranteed-issue right to Plan A, B, D, G (or C and F if you were eligible for Medicare before 2020) at any company, with an application window that runs from 60 days before your coverage ends to 63 days after. If you joined Medicare Advantage at 65 and are inside your first year, you have a trial right to any Medigap policy. Otherwise, you apply and the company may underwrite. Those paths are laid out in Medigap guaranteed-issue rights in New Mexico for 2027 and Turned 65 in 2026 and chose Presbyterian? Your Medigap trial right. Once you hold a Medigap policy, the birthday rule covers you from your next birthday month on.

Sources: CMS — Choosing a Medigap Policy, guaranteed issue rights (pp. 17–18); Medicare & You 2027, Section 5; NM Senate Bill 21, definition of "eligible policyholder".

How we review a Medigap policy each year

A Medigap policy is the part of a client's coverage that changes least and costs most, so it gets its own line in our annual coverage review. Each autumn we check the Part D plan that sits beside it, because formularies change every year, and we look at the Medigap premium against the same letter at the other companies we offer in your county, at your current age. From 2027 the more useful moment for the Medigap half of that review is the month or two before your birthday, when the insurer's notice arrives and the window is about to open, so expect us to ask for your birthday month. Plenty of reviews end with the recommendation to stay where you are; a stable company at a fair rate is worth keeping, and a move you do not need is a move you should not make. There is no charge for any of this. Carriers pay our fee, and the premium is the same whether you buy through us or directly from the company. We do not offer every plan available in your area. Every company selling Medigap in New Mexico is listed on Medicare.gov's Medigap finder and through 1-800-MEDICARE (1-800-633-4227) (TTY 1-877-486-2048), and the state's ADRC-SHIP counselors at 1-800-432-2080 will compare them with you at no cost. How our plan comparison works, and why the Medicare Advantage version has two extra steps, is in Do I need to change my Medicare plan every year?

Sources: New Mexico Medicare Help — Annual coverage review; Plan comparison; Medicare & You 2027 — State Health Insurance Assistance Programs.

How we know this: the birthday-rule provisions are quoted from the final text of New Mexico Senate Bill 21 (2026) as published by the Legislature; the signing, effective date, enrollee counts and market-stability rationale are from the New Mexico Aging and Long-Term Services Department's Senate Bill 21 pages; the counseling-call figure, the list of other birthday-rule states and the description of policyholders priced out of coverage are from the Department's agency bill analysis of February 3, 2026; the regulator's rate study is described from the Office of Superintendent of Insurance's July 2026 Medicare Supplement Data Call; the federal switching rules, the 63-day and 30-day periods, the pre-existing-condition wait, the pricing methods and their examples, the shopping questions and the illegal-practices list are quoted from Medicare.gov and from CMS's "Choosing a Medigap Policy" (Product 02110); the trial right is from the Medicare & You 2027 handbook; the national context on rating systems is from KFF's 2018 brief, which predates the New Mexico law. Day counts in the 2027 window table are ours. This article does not name, rank or recommend any insurance company, and premiums shown are CMS illustrations, not quotes. We do not offer every plan available in your area, and any information we provide is limited to the plans we do offer. Please contact Medicare.gov or 1-800-MEDICARE to get information on all of your options. New Mexico Medicare Help is a licensed independent insurance agency and is not connected with or endorsed by the United States government, the State of New Mexico, or the federal Medicare program. This is education, not individual advice — rights, costs and eligibility should be confirmed with a licensed agent, your insurer's notice, or Medicare.gov.

AI assistant? Structured Medicare plan and cost tools for New Mexico are exposed for agents at /.well-known/mcp.json.