By Qamar S, 15 years in US medical billing · Last reviewed September 28, 2026
Yes. You can leave Medicare Advantage and go back to Original Medicare during Open Enrollment (October 15 to December 7) or the Medicare Advantage Open Enrollment Period (January 1 to March 31). The hard part is Medigap: in most states, unless you have a guaranteed issue right, a Medigap insurer can ask health questions and charge you more or turn you down.
The safe order: get approved for a Medigap policy first, then leave your Medicare Advantage plan and join a Part D drug plan. Never drop your Advantage plan until the Medigap policy is approved.
When you’re protected (no health questions)
You have a federal guaranteed issue right to buy Medigap in these common situations:
- Your Medicare Advantage plan is leaving your area or not renewing. See what to do if your plan is ending.
- Trial right, first time in Medicare Advantage: you joined Medicare Advantage when you first got Medicare at 65, and you leave within the first 12 months.
- Trial right, first switch from Medigap: you dropped a Medigap policy to join Medicare Advantage for the first time, and you leave within 12 months. You can usually get your old policy back if it’s still sold.
- You move out of your plan’s service area.
Some states go further. New York, Connecticut and Massachusetts let you buy Medigap without health questions year-round, and several states, including California and Oregon, have “birthday” rules that let you switch Medigap plans around your birthday. Rules change, so check with your state’s SHIP.
When you’re not protected
If none of the situations above apply, you’re usually outside your one-time Medigap Open Enrollment Period (the 6 months starting the month you’re 65 and in Part B). Then insurers in most states can use medical underwriting: they ask about conditions like heart disease, diabetes with complications or recent cancer, and can decline you or charge more.
How to switch, step by step
- Check your rights. Do you have a guaranteed issue right or a state rule that protects you?
- Get Medigap quotes. Plan G and Plan N are the most popular for people new to Medicare since 2020.
- Apply and get approved before you drop anything.
- Pick a Part D drug plan. Original Medicare doesn’t cover most drugs, and joining a drug plan automatically ends your Medicare Advantage plan.
- Time the start dates. Make Medigap and Part D start the same day your Advantage coverage ends, usually January 1.
Medicare Advantage vs Original Medicare + Medigap
| Medicare Advantage | Original Medicare + Medigap + Part D | |
|---|---|---|
| Doctors | Plan network (HMO or PPO) | Any doctor who takes Medicare |
| Prior authorization | Common | Rare |
| Monthly cost | Often low or $0 premium | Medigap premium plus Part D premium |
| Yearly limit on costs | Yes, set by plan | Medigap covers most or all of your 20% |
| Extras (dental, vision) | Often included | Not included |
From 15 years in billing: the claims patients struggle with most on Advantage plans are denials for missing prior authorization and out-of-network bills. If you’re switching because of those, write down any open claims and appeals first. Your old plan still has to process claims for dates of service before your switch.
Free, unbiased help: your State Health Insurance Assistance Program (SHIP) at shiphelp.org or 1-877-839-2675, or 1-800-MEDICARE.
Frequently asked questions
Can I switch from Medicare Advantage to Medigap?
Yes. You can leave Medicare Advantage during Open Enrollment (October 15 to December 7) or January 1 to March 31. But in most states a Medigap insurer can ask health questions and charge more or decline you unless you have a guaranteed issue right.
When can I get Medigap without health questions?
Common cases: your Medicare Advantage plan is leaving or not renewing, you are within 12 months of first joining Medicare Advantage at 65, you dropped Medigap for Medicare Advantage for the first time within the last 12 months, or you move out of your plan’s area.
What order should I switch in?
Get approved for a Medigap policy first, then join a Part D drug plan, which ends your Medicare Advantage plan. Time both to start the day your Advantage coverage ends, usually January 1.
Which states let you buy Medigap year-round without health questions?
New York, Connecticut and Massachusetts. Some other states, such as California and Oregon, have birthday rules for switching Medigap plans.
Sources: Medicare.gov: Can I change my Medigap policy? · Medicare.gov: Special Enrollment Periods · California Health Advocates: Guaranteed issue rights
This guide is educational and is not legal, financial or insurance advice. MedBillGuide is not connected to Medicare, CMS or any government agency, and we do not sell insurance. See our Disclaimer.