Medicare in Oregon

Medicare Advantage plans allow beneficiaries to obtain their coverage via private plans instead of through Original — or traditional — Medicare (the federal government’s fee-for-service program). These plans are one option for consumers who desire additional benefits beyond what Original Medicare offers, and those who prefer lower total premiums (versus Medigap + stand-alone Part D) in trade for potentially higher out-of-pocket costs and more limited access to medical providers.

Medicare Advantage plans are run by private insurers that have more limited provider networks than Original Medicare. Although Medicare Advantage plans have caps on out-of-pocket costs (unlike Original Medicare on its own), the out-of-pocket exposure is generally more than a person would have if they purchased a Medigap plan and Part D plan to supplement Original Medicare.

Nearly 491,000 of Oregon’s Medicare beneficiaries had Medicare Advantage plans as of early 2023. That was more than 53% of the state’s total Medicare population, as opposed to about 48% of Medicare beneficiaries nationwide who have opted for private Medicare coverage (not counting supplemental Medigap and Part D coverage that’s purchased in addition to Original Medicare).

There are Medicare Advantage plans available in all 36 counties in Oregon. But the number of plans for sale in 2023 varies from as few as two to as many as 61, depending on the county.

Medicare Advantage enrollment is available during the annual election period each fall (October 15 to December 7). And people who are already enrolled in Medicare Advantage plans can also use the Medicare Advantage open enrollment period that runs from January through March. It allows them to switch to a different Medicare Advantage plan or switch to Original Medicare.

Medigap plans are subject to various federal rules, but states also have a lot of say in how the plans operate. Oregon has a rule to ensure that Medigap enrollees aren’t stuck with their plan forever, regardless of their health status. And the state also guarantees access to Medigap plans for Medicare beneficiaries under age 65.

Medigap plans are standardized at the federal level, and federal law guarantees access to Medigap plans when people turn 65 and enroll in Medicare Part B (you have to also be enrolled in Medicare Part A in order to have Medigap, but the six-month open enrollment period for Medigap plans starts when you are at least 65 and enrolled in Part B).

But unlike Medicare Advantage and Part D, there’s no federal annual open enrollment period for Medigap plans; once that initial six-month window ends, it’s gone forever (except for the limited circumstances that trigger a guaranteed-issue right for Medigap). People who want to switch to a different Medigap plan are generally subject to medical underwriting, so healthy people can change plans, but those with pre-existing medical conditions may not be able to do so. And people under age 65 (who are eligible for Medicare due to a disability or having end-stage renal disease or ALS) are not guaranteed access to Medigap under federal rules.

To address this, Oregon implemented a “birthday rule” in 2013 that allows Medigap enrollees an annual opportunity to change to a plan with equal or lesser benefits during the 30 days following their birthday. The new plan is guaranteed issue during that window.

Oregon also allows Medicare beneficiaries under age 65 a six-month window (after enrolling in Medicare Part B) during which they have a guaranteed-issue right to a Medigap plan. Eligible enrollees can select a Medigap plan with no medical underwriting during a six-month window after they enroll in Medicare Part B, and the premium cannot exceed the premiums that are charged to enrollees who are 65.

In 2025, there are 21 insurers that offer Medigap plans in Oregon.¹

There are three approaches to premiums that Medigap insurers can use: Attained-age rating, issue-age rating, and community rating. Oregon does not mandate one or the other, so most insurers in the state use attained-age rating. That means premiums increase as the enrollee gets older. There are a few Medigap insurers that use issue-age rating (premiums are based on the age the person was when they enrolled), while the rest use attained-age rating.

According to an AHIP analysis, 192,985 Medicare beneficiaries in Oregon had Medigap coverage as of 2021.

Original Medicare does not cover prescription drugs, so most beneficiaries rely on optional Part D coverage to help cover drug costs. Some enrollees have prescription coverage via an employer-sponsored plan, but Medicare Part D plans are available for those who need to obtain their own prescription coverage (prior to 2006, there were some Medigap plans that included prescription coverage; those are no longer for sale, but people who still have them are allowed to keep them).

Medicare Part D was created under the Medicare Modernization Act of 2003.  Medicare Part D coverage can be purchased on a stand-alone basis or integrated with a Medicare Advantage plan (almost nine out of ten Medicare Advantage plans provide coverage for prescription drugs).

As of early 2023, there were 260,693 Oregon Medicare beneficiaries enrolled in stand-alone Medicare Part D plans. Another 466,097 beneficiaries had Medicare Part D coverage integrated with their Medicare Advantage plans.

For 2023 coverage, there are 24 stand-alone Medicare Part D plans available in Oregon, with premiums ranging from under $2/month to $113/month.

Medicare Part D enrollment is available during Medicare’s annual open enrollment period in the fall (October 15 to December 7). Plan selections made during this window are effective as of the following January.

Many Medicare beneficiaries receive financial assistance through Medicaid with the cost of Medicare premiums and services Medicare doesn’t cover – such as long-term care.

Our guide to financial assistance for Medicare enrollees in Oregon includes overviews of these benefits, including Medicare Savings Programs, long-term care coverage, and eligibility guidelines for assistance.

If you need help with your Medicare application in Oregon or have questions about Medicare eligibility in Oregon, look into one of these resources. You can visit a website and browse for information, or call for more personalized assistance.

• Senior Health Insurance Benefits Assistance (SHIBA) can provide help with a wide range of issues related to Medicare in Oregon. SHIBA also maintains a page of FAQs about Medicare that include provisions specific to Oregon, such as the Medigap protections. The phone number is 1-800-722-4134.
• The Medicare Rights Center is also an excellent resource for Medicare-related questions. The national helpline number is 1-800-333-4114.