Medicare, Medicaid, and the marketplace: who qualifies

Eligibility rules for Medicare, Medicaid, and the ACA marketplace differ in important ways, but they intersect around age, disability, income, and whether you already have other coverage. Knowing the basics can help you identify the right path to comprehensive coverage in your state and understand what documents you may need when applying through local services in your area.

This article is for informational purposes only and should not be considered medical advice. Please consult a qualified healthcare professional for personalized guidance and treatment.

Healthcare and Health Insurance: Medicare eligibility

Medicare primarily serves people age 65 and older in the United States, as well as certain younger individuals with disabilities. You generally qualify at 65 if you are a U.S. citizen or a lawful permanent resident who has lived in the country for at least five years. Many people receive Part A without a monthly premium if they or a spouse have enough work credits; others can buy in. People under 65 may qualify after receiving Social Security Disability Insurance for 24 months, or immediately upon a diagnosis of end-stage renal disease or ALS. Enrollment periods can affect costs and late penalties, so note your Initial Enrollment Period and any Special Enrollment Periods tied to employer coverage.

Medicaid and health insurance qualifications

Medicaid provides coverage based on income, household size, and specific eligibility categories, with rules set by both federal law and your state. In states that expanded Medicaid, most adults qualify if household income is at or below 138% of the federal poverty level (FPL). In non-expansion states, adults typically qualify only if they meet a category such as pregnancy, parent/caretaker relative, disability, or age 65+. Children and many pregnant people often have higher income thresholds, sometimes through the Children’s Health Insurance Program (CHIP). Financial rules for people who are aged, blind, or disabled may include asset considerations, while most other groups use modified adjusted gross income (MAGI). You must also meet nonfinancial requirements such as state residency and citizenship or qualified immigration status, and you apply through your state Medicaid agency in your area.

Get insights on health insurance for the marketplace

The ACA marketplace offers private health insurance plans, with eligibility anchored to your tax household and current access to other coverage. You can buy a marketplace plan if you live in the United States, are a U.S. citizen or lawfully present, are not incarcerated (pending disposition excepted), and are not eligible for Medicare. If you have an offer of “affordable” employer coverage that meets minimum value, you typically cannot receive marketplace subsidies. Premium tax credits lower monthly premiums for many households; they are generally available when the benchmark plan would cost a specified share of your household income. Cost-sharing reductions are available for eligible enrollees who choose a silver plan and have incomes within defined FPL ranges. Open Enrollment happens annually, but Special Enrollment Periods allow you to enroll after qualifying life events such as losing other coverage, moving to a new state, changes in household size, or changes in immigration status. People in some non-expansion states may encounter a “coverage gap” if their income is below the marketplace subsidy threshold but above their state’s Medicaid limit; state-specific options vary, so check resources in your area.

How immigration status and residency affect eligibility

All three programs require that you live in the state where you apply. U.S. citizens qualify based on each program’s rules for age, disability, and income. Many lawfully present immigrants can enroll in marketplace plans and may receive subsidies, depending on income. Medicaid eligibility for immigrants varies by state and category; some states provide full-scope coverage while others offer limited-scope or emergency Medicaid. For Medicare, lawful permanent residents generally need five years of residency to qualify based on age, and may face different premium rules if they lack sufficient work history. If your household includes people with mixed statuses, you can still apply for eligible family members without disclosing information about those who do not seek coverage.

Income, household size, and documentation basics

For Medicaid and marketplace applications, your eligibility hinges on the size of your tax household and projected annual income. MAGI rules consider wages, self-employment, unemployment benefits, and certain other income, but exclude some sources like child support received. Be prepared to provide Social Security numbers for applicants, proof of residency in your state, and, when relevant, immigration documents. Marketplace applications also require an email, tax filing information, and details on any employer coverage offered to you or a household member. Medicare applicants typically work through Social Security; timing matters to avoid gaps in coverage or late-enrollment penalties. Keeping recent pay stubs, a prior year’s tax return, and employer coverage forms helps streamline applications with local services in your area.

Coordinating benefits and avoiding gaps

Individuals sometimes transition between programs—turning 65 while on Medicaid, gaining or losing a job with employer benefits, or qualifying for disability. If you approach 65, review how your current coverage interacts with Medicare, including whether Medicaid may wrap around Medicare to help with premiums and cost sharing through programs like Medicare Savings Programs. If you lose employer coverage, you may qualify for a Special Enrollment Period for either the marketplace or Medicare, depending on your age and status. Keep effective dates in mind: marketplace plans generally start the first of the month after selection deadlines, while Medicare and Medicaid start dates follow program-specific rules. Planning around these timelines reduces the risk of a coverage gap.

Practical tips in your area

• Use your state’s official Medicaid website to confirm income limits and covered categories.
• Check your state-based marketplace (or HealthCare.gov) for plan options, eligibility screens, and enrollment dates.
• For Medicare, review your Initial Enrollment Period dates and consider contacting a State Health Insurance Assistance Program for unbiased counseling.
• Keep records of major life events—moves, births, adoptions, marriage, or loss of coverage—to document Special Enrollment Periods.

Conclusion

Eligibility for Medicare centers on age and certain disabilities; Medicaid hinges on income, household size, and category under state and federal rules; and the marketplace serves those without other qualifying coverage, with subsidies based on income and household factors. Understanding these distinctions—and the role of residency and immigration status—can help you align your path to coverage with the resources available in your state and community.