Oregon Medigap & the Birthday Rule Explained (2026)

Oregon's Medicare Supplement (Medigap) "birthday rule" lets policyholders switch plans once a year with no medical underwriting, no matter their health. Each year, Oregon gives you a 60-day window, opening 30 days before your birthday and closing 30 days after it, to move to an equal-or-lesser Medigap plan from any insurer, a protection the state adopted to help people stuck in policies with steep annual rate hikes. This guide explains how Oregon's birthday rule works, how to use it, how the standardized A-through-N plans fit together, which plans are closed to newer enrollees, and who regulates Medigap in the state.

How Medigap works in Oregon

A Medigap policy is private insurance that pays the deductibles and coinsurance Original Medicare leaves to you. Medigap (Medicare Supplement Insurance) works only alongside Original Medicare, not with a Medicare Advantage plan, and each policy covers one person. A married couple who both want coverage need two separate policies.1

Oregon uses the federal standardized framework. Medigap is sold as lettered plans, A through N, and the benefits inside each letter are fixed by federal rule. A Plan G from one Oregon insurer covers exactly what a Plan G from another covers. Insurers compete on price, service, and rate stability, not on what the plan pays. That makes the plan letter your first decision and the insurer your second.

The gaps Medigap closes are real. In 2026, after you meet the annual Part B deductible of $283, Original Medicare still leaves you 20% coinsurance on the approved amount for most outpatient care, with no annual cap. Part A adds an inpatient hospital deductible of $1,736 per benefit period in 2026, and because a new benefit period can begin more than once in a year, that deductible can apply more than once. Medigap caps that exposure.2

The Oregon birthday rule

Oregon's annual protection is the birthday rule. Under Oregon law, a Medigap policyholder has a 60-day window each year, starting 30 days before their birthday and ending 30 days after it, during which they may switch without medical underwriting, and guaranteed regardless of health, to a Medigap policy of the same plan type or lesser benefits offered by any insurer, according to Oregon SHIBA. Oregon adopted the rule in response to consumer complaints about being locked into plans with large annual rate increases.3

The practical value is that you are not locked into your current insurer's price. Medigap benefits inside a letter are identical across companies, but premiums are not, and an insurer's rates can climb faster than a competitor's over time. The birthday rule lets you move your same Plan G (or any equal-or-lesser plan) to a lower-priced carrier once a year without proving you're healthy enough to qualify. New coverage typically begins on the first of the month after your application.3

The "same plan type or lesser benefits" limit is the key constraint. You can move sideways (Plan G to another Plan G) or down to a less generous letter (Plan G to Plan N), but the birthday rule does not let you move up to a more comprehensive plan. As Oregon's Division of Financial Regulation puts it, a 2010 Plan F enrollee can switch to any 2010 Medicare Supplement Plan A through N, except an Innovative Plan F. Moving up still requires medical underwriting outside a guaranteed-issue window, so a switch from Plan N to Plan G is not protected by the birthday rule.

How to use the Oregon birthday rule

The window is time-limited and the timing rules are specific, so plan the switch before your birthday arrives. Oregon's birthday rule guarantees the switch to a same-type-or-lesser plan from any insurer with no underwriting, so the work is mostly timing and comparison.3

Because the benefits inside a letter are standardized, a same-letter switch changes your premium and insurer, not your coverage. If you move to a lesser letter, your cost-sharing changes to match that letter.

Plan G and Plan N: the common choices

For someone newly eligible for Medicare, the practical choice in Oregon narrows to two plans.

Plan G is the most complete plan still available to people who became eligible on or after January 1, 2020. It covers every gap in Original Medicare except the annual Part B deductible: the Part A hospital deductible, Part A and Part B coinsurance, skilled nursing facility coinsurance, and Part B excess charges. After you pay that one Part B deductible for the year, a Plan G holder generally has no further cost-sharing on Medicare-covered services.4

Plan N covers the same major gaps but shifts a little cost back to you. It pays the Part B coinsurance in full except for a copay of up to $20 for some office visits and up to $50 for emergency-room visits that don't lead to an inpatient admission, and it does not cover Part B excess charges. In exchange, Plan N premiums are usually lower than Plan G premiums.1

Plans C and F are closed to newer enrollees

Plans C and F once covered the annual Part B deductible on top of the other gaps, which made Plan F the most complete plan on the market. Under the Medicare Access and CHIP Reauthorization Act of 2015 (MACRA), any Medigap plan that pays the Part B deductible is closed to people who first became eligible for Medicare on or after January 1, 2020.4

The closure works by eligibility date, not purchase date. If you became eligible for Medicare before January 1, 2020, you can still buy or keep Plan C or Plan F in Oregon. If you became eligible on or after that date, those two plans are off the table, which is why Plan G has become the default top-tier choice for newer enrollees: it's identical to Plan F except that you pay the one Part B deductible yourself.

When you can buy or switch in Oregon

Oregon gives you more than one protected window. Three matter most.

• The federal Medigap Open Enrollment Period. This is a one-time, six-month window that begins the first month you're both age 65 or older and enrolled in Medicare Part B. During it, insurers must sell you any Medigap policy they offer at their best available rate regardless of your health, with no medical underwriting. This is the single best time to buy, because you can choose any plan, including Plan G. Read more about the Medigap Open Enrollment Period.4
• The annual birthday rule. The 60-day window described above, repeating each year, for switching to an equal-or-lesser plan from any insurer with no underwriting.
• Federal guaranteed-issue rights. Certain life events, such as losing other coverage or an insurer leaving the market, trigger a federal guaranteed-issue right to buy specific plans without underwriting.

Outside these windows, an Oregon insurer can require medical underwriting and charge more, or decline to sell you a policy, based on your health. That's why the choice between Plan G and Plan N is best made during your six-month open enrollment: if you start on Plan N to save on premiums and later want Plan G, the birthday rule won't cover that move up, and underwriting could make it expensive or impossible.

What Medigap costs and how it's priced in Oregon

Medigap premiums vary widely. The benefits inside a letter are fixed, but the price is not: it depends on the insurer, your age, and in many cases your gender and tobacco use, and CMS does not set Medigap premiums. There is no single Oregon rate, so compare quotes for the same plan letter across several carriers.2

Insurers use one of three pricing methods, described in the medicare.gov guide Choosing a Medigap Policy, which shapes how your premium changes as you age:

• Community-rated policies charge everyone the same premium regardless of age.
• Issue-age-rated policies base your premium on your age when you buy, and that starting point doesn't rise simply because you get older.
• Attained-age-rated policies start lower but increase as you age, so a low first-year quote can climb over time.

Ask which method each insurer uses, not just the first-year premium. The birthday rule pairs well with this, and it is exactly the problem Oregon designed the rule to solve: if your attained-age policy climbs, the annual window lets you move an equal-or-lesser plan to a cheaper carrier without underwriting. Note that Medigap does not include prescription drug coverage, so you add a separate Part D plan for that.

Who regulates Medigap in Oregon

Oregon Medigap policies are regulated by the Oregon Division of Financial Regulation (DFR), which oversees the insurers that sell these policies and handles consumer complaints. For free, unbiased one-on-one counseling on Medigap and the birthday rule, Oregon's State Health Insurance Benefits Assistance program, Oregon SHIBA, can help, and its statewide helpline is 1-800-722-4134.5

Learn More

Ready to act? If your birthday window is coming up, call Oregon SHIBA at 1-800-722-4134 for free, unbiased help comparing Medigap plans, or start at Oregon SHIBA.

The information on Brevy.com is for educational purposes only and is not a substitute for professional legal, financial, or medical advice. Rules vary by state and program and change frequently. Always verify with the relevant agency or a qualified professional. Brevy is not a law firm, financial advisor, or healthcare provider.