Probably not.

Even though most employer-sponsored health plans extend coverage to domestic partners, Medicare does not offer the same benefits and rights as legal spouses.

Legal spouses’ rights include a special enrollment period for Medicare Part B. Legal spouses who become eligible for Medicare can delay signing up, without risking a late penalty, if they have insurance through their partner’s job. When that spouse’s employement ends and you lose that coverage, you have an eight-month grace period to enroll in Part B without a penalty.

There are two exceptions to this rule though.

Common-law marriage. If you and your partner live in a state that recognizes  common-law marriages and your relationship meets the legal definition of common-law marriage in that state, Medicare will consider you spouses and apply the spousal rules. 

Disability. People who receive Social Security Disability Insurance (SSDI) can qualify for Medicare before age 65. Domestic partners with a disability may be allowed a special enrollment period if they meet all these conditions: 

• They are younger than 65 and entitled to Medicare based on their disability.
• They are covered under their partner’s workplace insurance.
• That workplace employs at least 100 people. 

For eligibility based on disability, you get a special enrollment period if you received coverage from what Medicare considers a large group health plan via your employer or that of a “family member.” Domestic partners don’t meet Medicare’s definition of a spouse, but they do count as family members for SEP purposes. 

But remember that once you hit 65, your Medicare eligibility is based solely on age. The disability exceptions become irrelevant. At that point, if you don’t sign up for Part B — or marry your partner — you’ll likely face those late enrollment charges down the road.