CHRISTUS Health Plan is shutting down its Medicare Advantage business at the end of the year. Its Guardian, Plus and Complete HMO plans stop on December 31, 2026, leaving members in Texas and New Mexico to choose new coverage for 2027.
The exit lands in the middle of Medicare’s fall enrollment season. Members who do nothing will not lose Medicare itself, but they will lose the extra benefits and drug coverage tied to their plan, and the plan’s own guidance points them to a December 7 decision date.
Which CHRISTUS plans end and who is affected
On a member notice about 2027 coverage, CHRISTUS Health Plan says it has decided to end its Medicare Advantage plans. The notice names the Guardian (HMO) Medicare Advantage-only plan and the Plus (HMO) and Complete (HMO) plans, and says coverage under them ends December 31, 2026.
The plan does not give a member count on that page. Reporting on the CMS plan data released September 30 put the total at nearly 9,000 Medicare Advantage members across Texas and New Mexico, citing Modern Healthcare. That report said CHRISTUS sold Medicare Advantage in 36 Texas counties and 8 New Mexico counties in 2026, including East Texas, the Corpus Christi and Beaumont areas, and the region around Santa Fe and Albuquerque.
The same report said the company’s individual and family marketplace plans were not on the CMS exit list, and that CHRISTUS hospitals and clinics are not affected. The change is about the insurance product, not about where members can be treated next year under a new plan.
What the CHRISTUS exit notice leaves undone: A Guardian, Plus or Complete member has to weigh a replacement Medicare Advantage plan against Original Medicare with drug coverage, plan by plan, on premiums, prescriptions and doctors, and a cost calculator spreadsheet built for that side-by-side check is in The 2027 Medicare Open Enrollment Decision Kit.
The December 7 choice and the February backup window
Medicare’s annual Open Enrollment Period runs from October 15 through December 7. CHRISTUS tells members to enroll in a new plan by December 7, 2026, so that coverage starts on January 1, the same day the old plans stop.
Members of a plan whose Medicare contract is not renewed also get a separate special enrollment period. Medicare.gov says that window runs from December 8 through the last day of February of the following year. CHRISTUS puts its version at December 8, 2026 through February 28, 2027.
The same Medicare.gov page explains what happens to anyone who misses both windows: a person who does not join another Medicare Advantage plan before the current one ends is enrolled in Original Medicare. CHRISTUS says that default takes effect January 1, 2027.
Why the default to Original Medicare can cost money
Landing in Original Medicare by default keeps hospital and doctor coverage, but it changes the bill. Original Medicare does not include the prescription drug coverage that most Medicare Advantage HMOs bundle in, so a member who simply waits would need to add a separate Part D drug plan to keep prescriptions covered.
Original Medicare also has no yearly cap on out-of-pocket costs for hospital and doctor care. Many people who leave Medicare Advantage therefore look at a Medicare Supplement policy, also called Medigap, to cover the deductibles and coinsurance that Original Medicare leaves behind. That is where the timing of the CHRISTUS exit matters most.
The Medigap right that comes with a plan ending
Outside of protected situations, Medigap insurers in most states can price or turn down an applicant based on health history. A Medicare Advantage plan leaving Medicare is one of the protected situations. Medicare.gov says people in that position have the right to buy any Medigap policy sold by an insurance company in their state, and that they can apply as early as 60 days before their Medicare Advantage coverage ends and no later than 63 days after it ends.
CHRISTUS says members automatically qualify for that federal guaranteed-issue right, and it puts the last day to apply at March 4, 2027. A member who wants a supplement and waits past that date goes back to ordinary underwriting rules, where a heart condition, diabetes or another health history can mean a higher price or a denial.
Rewards, records and the numbers to call
The CHRISTUS notice flags two smaller losses that are easy to miss. Members can no longer earn Rewards and Incentives dollars after December 31, 2026, and the plan says online portal records stay available through March 31, 2028, so claims history and explanation-of-benefits records can be saved before access ends.
CHRISTUS Member Services answers at 1-844-282-3026 (TTY 711), seven days a week from 8 a.m. to 8 p.m. local time. Medicare itself answers at 1-800-MEDICARE (1-800-633-4227) around the clock. Free, unbiased counseling is available from each state’s health insurance assistance program: 1-800-252-9240 in Texas and 1-800-432-2080 in New Mexico.
The details that decide a replacement plan are the same for every member: whether each doctor and hospital is in the 2027 network, whether each prescription is on the plan’s drug list and at what tier, and what the full year costs once premiums, deductibles and copays are added up. A plan that looks similar on paper can still drop a specialist or move a key drug to a costlier tier.
Picking coverage after the CHRISTUS exit
CHRISTUS Health Plan members in Texas and New Mexico are working against two separate clocks: Open Enrollment closes December 7, and the federal Medigap guaranteed-issue right runs on its own schedule around the January 1 cutoff. Choosing between a new Medicare Advantage plan and Original Medicare with a supplement means lining up networks, drug lists and those dates in one place.
The 2027 Medicare Open Enrollment Decision Kit sets the Open Enrollment calendar beside the Medigap guaranteed-issue rights that apply when a Medicare Advantage plan leaves, with a call script for checking both paths against a member’s own doctors and insurers.
Read the Medigap guaranteed-issue section in The 2027 Medicare Open Enrollment Decision Kit.
This article was created with AI assistance and reviewed for accuracy against CHRISTUS Health Plan’s 2027 member notice and Medicare.gov guidance.
Nathaniel Cross focuses on retirement planning, employer benefits, and long-term income security. His writing covers pensions, social programs, investment vehicles, and strategies designed to protect financial independence later in life. At The Daily Overview, Nathaniel provides practical insight to help readers plan with confidence and foresight.
