Every January a familiar call comes in. A member of an Advantage plan has had a new year of bills, a doctor has left the network, or the plan has changed what it covers, and they ask whether it is too late to do anything. For most people already in a Medicare Advantage plan it is not, because the calendar holds a second, smaller window in the first three months of the year. It carries one tight rule: you get a single change, so know the details before you use it.
The Short Version: Key Takeaways
- The window: January 1 through March 31, 2027, for people already in a Medicare Advantage plan (42 CFR 422.62).
- One change only: switch to another Advantage plan, or return to Original Medicare. It does not let you move from Original Medicare into Advantage.
- Start dates: a change starts on the first day of the month after the plan gets your request.
- Idaho's 2027 shake-up: 50,256 members of individual Advantage plans sit in plan IDs the CMS crosswalk lists as not offered in 2027.
- Medigap is the catch: leaving for Original Medicare does not guarantee a Medigap policy in Idaho unless you are in a listed situation, so apply first.
Not sure whether to stay, switch or go back to Original Medicare?
Send us your plan name, doctors and prescriptions. We show you what each of the three paths would change before you spend your one election.
Call or text 208-350-9933 Send us a messageWhat the Medicare Advantage Open Enrollment Period Is
Medicare gives people two yearly chances to change Advantage plans. The big one is the Annual Enrollment Period, October 15 through December 7. The Medicare Advantage Open Enrollment Period, or MA OEP, is the quiet second chance. It covers the first three months of the calendar year and belongs only to people already enrolled in an Advantage plan. It is a correction window, not a second open enrollment.
| Question | Answer |
|---|---|
| Dates | January 1 through March 31 (2027: Friday, January 1 through Wednesday, March 31) |
| Who | People enrolled in a Medicare Advantage plan, with or without drug coverage |
| How many changes | One election in the three months |
| What you can do | Enroll in another Advantage plan, or disenroll to Original Medicare |
| Drug coverage | You may also enroll in or leave Part D, including a stand-alone plan if you return to Original Medicare |
| What you cannot do | Move from Original Medicare into an Advantage plan |
Source: 42 CFR 422.62(a)(3) and 42 CFR 423.38(e), eCFR as of November 9, 2026; CMS publication 11219.
Who Can Use It, and Who Cannot
| Your situation on January 1, 2027 | Can you use it? | What to know |
|---|---|---|
| In a Medicare Advantage plan | Yes, once | Switch plans or return to Original Medicare |
| In Original Medicare, with or without Medigap | No | You cannot join an Advantage plan or change a stand-alone drug plan in these months without a special period |
| New to Medicare and in an Advantage plan | Separate window | One change from the month you have Parts A and B through the last day of the third month |
| Living in a long-term care institution as CMS defines it | Not limited to one change | Changes allowed while you live there and through the second month after you leave |
| Your plan is not offered in 2027 | Separate special period | December 8 through the last day of February; the one-change limit does not apply to changes made in a special period |
Source: 42 CFR 422.62(a)(3) and (a)(4), eCFR as of November 9, 2026; CMS publication 11219.
A first-time Advantage member also has a one-year trial period to go back to Original Medicare, and Idaho attaches a Medigap guarantee to it (IDAPA 18.04.10, section 041). That is a different right from the January to March window.
The 2027 Calendar and When Changes Start
| Window | Dates | Who | Changes |
|---|---|---|---|
| Annual Enrollment Period | October 15 through December 7, 2026 | Everyone with Medicare | More than one change allowed; starts January 1, 2027 |
| Special period, plan not renewed | December 8, 2026 through February 28, 2027 | Members of a plan not renewed | Switch plans; Original Medicare if none chosen |
| MA Open Enrollment Period | January 1 through March 31, 2027 | Advantage members | One election |
Source: CMS publication 11219; 42 CFR 422.62; CMS Idaho fact sheet.
A change starts on the first day of the month after the plan gets your request (CMS publication 11219). A January request starts February 1, February starts March 1, and a request on March 31 starts April 1. Your current plan stays in force until then, so do not wait for the last week.
Your Three Choices
| Path | Drug coverage | Medigap | Main watch-out |
|---|---|---|---|
| Stay | Unchanged | Not involved | You can still use your one election later in the window |
| Switch Advantage plans | New plan, with or without drug coverage | Not involved | Doctors, hospital and pharmacy may be outside the new network |
| Return to Original Medicare | Stand-alone Part D plan available | Separate application; guaranteed only in listed situations | No out-of-pocket maximum without Medigap |
Source: 42 CFR 422.62(a)(3); 42 CFR 423.38(e); IDAPA 18.04.10.
No path is better in the abstract. A member whose cardiologist is in another health system may do well to move to a PPO or return to Original Medicare. A member happy with a local HMO who only wants lower drug costs may do better to stay and revisit in the fall. Our post on Advantage versus Medicare Supplement in Idaho covers the structural differences.
Who Is in Advantage Plans in Idaho
The CMS October 2026 enrollment file records 188,659 Idaho members in local Medicare Advantage plans, about 45.3% of the 416,679 Idahoans CMS lists as enrolled in Medicare. CMS hides county cells of 10 or fewer, so the true number is higher, and the two figures come from different CMS files, so the share is approximate. About 66.7% of members are in HMO or HMO-POS plans, which usually mean a defined network and referrals.
| Segment | Plan IDs | Idaho members recorded | Share |
|---|---|---|---|
| Individual plans (not Special Needs, not employer) | 36 | 147,293 | 78.1% |
| Special Needs Plans | 10 | 31,170 | 16.5% |
| Employer or union group plans | 33 | 10,196 | 5.4% |
| All local Medicare Advantage plans | 79 | 188,659 | 100% |
Source: CMS Monthly Enrollment by Contract, Plan, State and County, October 2026, Idaho rows joined to the CMS contract information file; our count.
Idaho individual Advantage members by organization, split by whether their 2026 plan is offered in 2027
Source: CMS October 2026 enrollment file and CMS 2027 plan crosswalk, Idaho individual plans including Special Needs Plans.
| Organization (CMS marketing name) | Plan still offered | Plan not offered in 2027 | Total |
|---|---|---|---|
| UnitedHealthcare | 70,184 | 4,517 | 74,701 |
| Blue Cross of Idaho | 36,083 | 0 | 36,083 |
| Saint Alphonsus Health Plan | 0 | 22,888 | 22,888 |
| PacificSource Medicare | 0 | 17,057 | 17,057 |
| Humana | 11,606 | 3,065 | 14,671 |
| Molina Healthcare of Utah and Idaho | 10,090 | 2,729 | 12,819 |
| American Health Advantage of Utah | 244 | 0 | 244 |
| All organizations | 128,207 | 50,256 | 178,463 |
Source: CMS October 2026 enrollment file and CMS 2027 plan crosswalk; our count. "Still offered" means the 2026 plan ID has a 2027 renewal, which can include a smaller service area.
Plans Not Offered in 2027
Of the 178,463 members of individual plans above, 50,256, about 28.2%, are in a plan ID the CMS crosswalk marks "Terminated/Non-renewed Contract," which the CMS read-me defines as a 2026 plan no longer offered in 2027. Saint Alphonsus Health Plan and PacificSource account for most of it.
| Carrier | Plans | Plan IDs | Idaho members |
|---|---|---|---|
| Saint Alphonsus Health Plan | 4 | H6910-001, H6910-005, H3828-001, H6910-004 | 22,888 |
| PacificSource Medicare | 4 | H3864-024, H3864-034, H4754-006, H3864-030 | 17,057 |
| UnitedHealthcare (AARP Medicare Advantage ID-0010, ID-0011) | 2 | H2406-112, H2406-113 | 4,517 |
| Humana (one Special Needs Plan) | 2 | H5216-429, H7617-034 | 3,065 |
| Molina Healthcare (D-SNP) | 1 | H5628-014 | 2,729 |
| All carriers | 13 | 50,256 |
Source: CMS October 2026 enrollment file and CMS 2027 plan crosswalk (October 1, 2026); our count. Two of the 13 plans are Special Needs Plans (Molina D-SNP and HumanaChoice C-SNP).
If your plan is on this list, your plan should have sent a non-renewal notice. CMS lets you choose a different plan from December 8 through the last day of February, and if you choose none before the old plan ends you move to Original Medicare. It does not mean you lost Medicare. The special period is separate under the rule, and the one-change limit does not apply to changes made during it, so ask how it fits with the January to March window before you use either.
Idaho treats a plan discontinued in your area as a Medigap guaranteed-issue event. The window begins on the notice date and ends 63 days after coverage ends, about March 4, 2027 for coverage that ends December 31, 2026 (IDAPA 18.04.10, sections 041.02 and 041.03; the date is our count). Keep the notice.
Is your plan on the not-offered list?
Call us with the plan name on your card. We confirm what the notice means, price the 2027 options with your doctors and prescriptions, and, if Original Medicare is the better fit, line up the Medigap application and drug plan before your old coverage ends.
Call or text 208-350-9933 Send us a messageWhat Idaho Offers for 2027
| Measure | 2026 | 2027 |
|---|---|---|
| Medicare Advantage plans available in Idaho | 48 | 44 |
| Average monthly Medicare Advantage premium | $27.81 | $37.93 |
| Stand-alone Part D plans | Not in this CMS sheet | 8, lowest premium $5.30 a month |
Source: CMS, Medicare Open Enrollment in Idaho, 2027 (September 28, 2026).
Choice varies sharply by county. The Landscape file lists non-Special-Needs plans in 39 of Idaho's 44 counties, from 1 plan in Blaine County to 19 in Ada and Canyon counties. 33 plan IDs cover the state, 17 with a $0 Part C premium and 26 with drug coverage, by our count. Two carriers are new: St. Luke's Health Plan and Range Health appear in the crosswalk as initial contracts with no 2026 predecessor.
| Plans in the county | Counties | Examples |
|---|---|---|
| 1 plan | 1 | Blaine |
| 2 to 3 plans | 9 | Boundary, Cassia, Clearwater, Custer |
| 4 to 6 plans | 7 | Adams, Bear Lake, Camas, Caribou |
| 7 to 12 plans | 15 | Bannock, Bingham, Bonner, Bonneville |
| 13 or more plans | 7 | Ada, Boise, Canyon, Gem, Owyhee, Payette, Washington |
Source: CMS CY2027 Landscape file (202610), counted by county in our Idaho data; Special Needs Plans excluded.
Thin counties are where the one-change rule carries the most risk: with two or three plans, the one that fits a doctor's network may be the one you just left.
Going Back to Original Medicare: Medigap in Idaho
Original Medicare has no out-of-pocket maximum, so many people pair it with a Medigap policy. Idaho's open enrollment covers the six months that begin on the first day of the first month you are 65 and enrolled in Part B; in that period a carrier cannot deny you or price you by health (section 036). After that, the guarantee comes from specific events in section 041.
| Situation | Guaranteed issue? | Timing in the rule |
|---|---|---|
| Your Advantage plan is terminated or discontinued in your area | Yes | Notice date to 63 days after coverage ends |
| You move out of the plan's service area | Yes | 60 days before to 63 days after disenrollment |
| You had Medigap, joined Advantage for the first time, and leave within 12 months | Yes | 60 days before to 63 days after disenrollment |
| First joined Advantage when you became eligible for Part A and leave within 12 months | Yes | 60 days before to 63 days after disenrollment |
| You already hold Medigap and want a different policy | Yes, yearly | 63 days that begin on your birthday |
| In Advantage over a year, leaving by choice in January to March | Not listed in section 041 | The carrier may review your health history |
Source: IDAPA 18.04.10, sections 036, 041.02 and 041.03 (Idaho Department of Insurance, 2022 version); Bulletin No. 21-04. The last row is our reading of the rule, not a statement by the Department.
The birthday row describes people who already have Medigap and move to another policy. It does not rescue a late application from someone leaving Advantage; our answer on the Idaho birthday rule explains it. So apply for the Medigap policy first, wait for approval and a start date, and only then submit the disenrollment. See also Plan G versus Plan N in Idaho.
Drug Coverage When You Switch
| Path | Drug coverage outcome | Action needed |
|---|---|---|
| Switch to an Advantage plan with drug coverage | Drug coverage comes with the new plan | Check each medicine and the pharmacy network |
| Switch to an Advantage plan without drug coverage | The plan carries no drug coverage | Confirm other creditable drug coverage first |
| Return to Original Medicare | You may join a stand-alone Part D plan at the same time | Enroll in the drug plan in the same window |
| Return to Original Medicare, no drug plan | No drug coverage; a late enrollment penalty can follow after 63 days without creditable coverage | Do not leave this step for later |
Source: 42 CFR 423.38(e); 42 CFR 423.46; CMS publication 11219.
Every 2027 Part D plan uses the same standard benefit: a $700 deductible and a $2,400 out-of-pocket threshold (CMS CY2027 Rate Announcement). Formularies, tiers and pharmacies still differ across Idaho's 8 stand-alone plans, so we price your own prescription list. Our 2027 Part D post and Part D page go deeper.
Before You Use Your One Change
| Check | Question to ask |
|---|---|
| Doctors and hospital | Is each of my doctors and my usual hospital in the new plan's network? |
| Prescriptions and pharmacy | Is each medicine on the 2027 formulary, at what tier, and is my pharmacy in network? |
| Worst-case year | What is the most I would pay, and does Original Medicare have a Medigap backstop? |
| Medigap | Will a carrier issue me a policy, and from what date? |
| Special period | Does one apply, so I use the right window first? |
| Effective date | When does the old plan end and the new one begin? |
Source: Personal Touch's checklist, built from 42 CFR 422.62, 42 CFR 423.38 and IDAPA 18.04.10; not a CMS list.
We handle every line of that list in one conversation. See also our enrollment periods guide and the statewide Idaho Medicare page.
What to Watch Through March 31
- Your notices. A non-renewal letter is the first document to read. Keep it, because the Medigap guarantee can depend on its date.
- January claims. Deductibles reset, and the first pharmacy visit often shows whether the plan works as expected.
- February 28. The special period for non-renewed plans closes a month before the window does.
- March 31, 2027. The last day for the plan to receive your request.
- 2027 Part B figures. CMS has not yet published them, so we label them pending and will refresh the page when they arrive.
How We Built This Page
Window rules come from the eCFR text of 42 CFR 422.62 and 42 CFR 423.38, current as of November 9, 2026, and from CMS publication 11219, the agency's fact sheet on Medicare Advantage and drug plan enrollment periods, read in full on November 12, 2026. Member counts come from the CMS October 2026 enrollment file, filtered to Idaho local Advantage plan types and joined to the contract file. Plans "not offered in 2027" are those the CMS October 1, 2026 crosswalk marks "Terminated/Non-renewed Contract." Plan counts come from the CMS Landscape file as carried on our Idaho page, and Medigap rules from IDAPA 18.04.10 and Bulletin 21-04.
Limits: CMS hides enrollment cells of 10 or fewer, so member counts are floors. The crosswalk shows plan IDs, not individual members, and a plan can end in one county while renewing in another. The last row of the Medigap table is our reading, so confirm it with the carrier. This page is general education, not individual advice, and is current as of November 12, 2026. Personal Touch Ins. & Benefits, LLC does not offer every plan available in your area, and Medicare is a federal program.
Want to use your one change with confidence?
Send us your doctors, prescriptions and pharmacy before March 31. We compare the 2027 plans we represent side by side, tell you plainly what a switch would cost you in access and coverage, and meet by Zoom, phone or in Idaho City by appointment.
Call or text 208-350-9933 Send us a messageFrequently Asked Questions
When is the Medicare Advantage Open Enrollment Period in 2027?
It runs from January 1 through March 31, 2027, for people already in a Medicare Advantage plan. You get one election: switch to a different Advantage plan, or return to Original Medicare (42 CFR 422.62). A change starts on the first day of the next month. We confirm the dates and your plan with you at 208-350-9933.
Can I switch from Original Medicare to Medicare Advantage between January and March?
No. The window is for people already in an Advantage plan. If you are in Original Medicare, your next regular chance is the Annual Enrollment Period, October 15 through December 7, unless a Special Enrollment Period applies. We can check your situation with you at 208-350-9933.
Can I change plans more than once during the January to March window?
No, the window allows one election. If you switch in February and your doctor turns out to be out of network, you generally cannot switch again until the fall. We review your doctors, prescriptions and pharmacy with you first, free, at 208-350-9933.
If I go back to Original Medicare, can I buy a Medigap policy in Idaho?
You can apply, but approval is not guaranteed in every case. Idaho guarantees Medigap in the six months after you are 65 and in Part B, and in the situations listed in IDAPA 18.04.10 section 041, such as a plan that ends. A member who has been in Advantage for over a year and leaves by choice is not listed, so a carrier may review your health history. We check the Medigap side with you before you decide, at no cost, at 208-350-9933.
What happens to my drug coverage if I leave Medicare Advantage?
If you return to Original Medicare in the window, you may join a stand-alone Part D plan at the same time (42 CFR 423.38). Going 63 days or more without creditable drug coverage can bring a late enrollment penalty (42 CFR 423.46). We line up the drug plan with you at 208-350-9933.
My Medicare Advantage plan is not offered in 2027. Do I have to wait until March?
No. CMS gives members of a plan that is not renewed a special period from December 8 through the last day of February. Members who choose nothing return to Original Medicare when the plan ends. Call us at 208-350-9933 and we will walk through your notice with you.
Keep Reading
Sources
- 42 CFR 422.62, election of coverage under an MA plan (eCFR, current as of November 9, 2026), accessed November 12, 2026
- 42 CFR 423.38, enrollment periods for Part D, including coordination with the MA open enrollment period, accessed November 12, 2026
- 42 CFR 423.46, Part D late enrollment penalty, accessed November 12, 2026
- CMS Monthly Enrollment by Contract, Plan, State and County, October 2026, accessed November 12, 2026
- CMS 2027 Part C and D Plan Crosswalk (October 1, 2026), accessed November 12, 2026
- CMS CY2027 Medicare Advantage and Part D Landscape file (202610), accessed November 12, 2026
- CMS, Medicare Open Enrollment in Idaho, 2027 (state fact sheet, September 28, 2026), accessed November 12, 2026
- CMS CY2027 Medicare Advantage and Part D Rate Announcement, accessed November 12, 2026
- Idaho Department of Insurance, IDAPA 18.04.10, Medicare Supplement Insurance Standards, accessed November 12, 2026
- Idaho Department of Insurance, Bulletin No. 21-04 (Medicare Supplement birthday enrollment period), accessed November 12, 2026
Figures are labelled with the year they apply to and were checked against the official sources above on the date shown. This page is general education, not individual advice. Personal Touch Ins. & Benefits, LLC is not connected with or endorsed by the U.S. government or the federal Medicare program.