Understanding How Dual Medicare and Medicaid Plans Work Together

Being dual eligible means you qualify for both Medicare (federal health insurance, usually for people 65+) and Medicaid (state-administered insurance for people with limited income). When you have both, the two programs work together to cover more of your healthcare costs than either one alone. Approximately 12 million people are enrolled in both Medicare and Medicaid, referred to as dual-eligible individuals, receiving their primary health insurance coverage through Medicare and additional assistance from their state Medicaid program.

Despite representing a small portion of overall beneficiaries, dual-eligible individuals account for a disproportionate share of both Medicare and Medicaid spending. Understanding how these two programs coordinate is essential for anyone who qualifies for both. This article explains how dual eligibility works, what types of coverage exist, and how the programs function together to provide comprehensive health benefits.

What Is Dual Eligibility?

Dually eligible beneficiaries are people enrolled in both Medicare and Medicaid who are eligible by virtue of their age or disability and low incomes. This is a diverse population that includes people with multiple chronic conditions, physical disabilities, mental illness, and cognitive impairments such as dementia and developmental disabilities.

Dual eligibility is not automatic. To qualify, you must meet the eligibility requirements for both programs separately. Medicare eligibility generally requires being 65 or older, having a disability, or having end-stage renal disease. Medicaid eligibility is based on income and assets and is administered by individual states, so requirements vary by location. When you meet the criteria for both programs simultaneously, you become eligible for dual benefits.

Full-Benefit Versus Partial-Benefit Dual Eligibility

There are two categories of dual eligibility that determine what benefits you receive. Full-benefit duals have Medicare plus full Medicaid coverage, including long-term care. Partial-benefit duals have Medicare plus help through a Medicare Savings Program only, not full Medicaid.

Nearly 9 million people are "full-benefit" dual-eligible individuals, meaning they are eligible for Medicaid benefits that are not otherwise covered by Medicare, including long-term care, vision, and dental services. The remaining 3 million are "partial-benefit" dual-eligible individuals, and are only eligible for assistance with Medicare premiums and, in many cases, cost sharing through the Medicare Savings Programs. Which category you fall into depends on your income, assets, and state of residence.

How Payment Coordination Works

Primary and Secondary Payer Rules

When you have both Medicare and Medicaid, a clear payment order is established to avoid confusion and duplicate payments. Medicare pays first as the primary payer. Medicaid pays second, covering Medicare's premiums and cost-sharing and paying for services Medicare does not cover, most importantly long-term custodial care. This rule applies consistently to all dual-eligible individuals.

Medicaid typically pays for services that are covered by both Medicare and Medicaid, such as Medicare premiums and cost-sharing expenses like copayments or deductibles. When a service is covered only by Medicaid and not Medicare, Medicaid pays the full cost. Services not covered by Medicare, such as transportation, dental, vision, and most outpatient prescription drugs, are covered by Medicaid as the secondary payer.

📋 Coordination of Benefits Process

Coordination of benefits is a formal process that ensures claims are handled properly when you have multiple insurance plans. Coordination of benefits (COB) allows plans that provide health and/or prescription coverage for a person with Medicare to determine their respective payment responsibilities (i.e., determine which insurance plan has the primary payment responsibility and the extent to which the other plans will contribute when an individual is covered by more than one plan).

When you receive care, your healthcare provider submits the claim to Medicare first. If Medicare covers the service, it pays its portion. The claim is then sent to Medicaid, which reviews whether the service is covered under your Medicaid plan and pays any remaining costs you would otherwise owe. This coordination prevents gaps in coverage and reduces your out-of-pocket costs.

Coverage Comparison: Medicare Versus Medicaid

This table illustrates how the two programs complement each other. Having both is powerful because each program covers what the other does not. Medicare focuses on acute care and medical services, while Medicaid fills critical gaps in areas like long-term care, dental, and vision.

Prescription Drug Coverage and Extra Help

If you're dual eligible, Medicare — not Medicaid — covers your prescription drugs through Part D. You'll be automatically enrolled in a Part D plan, and you'll qualify for Extra Help, which dramatically reduces your drug costs. Full dual eligibles automatically qualify for Extra Help, the federal subsidy that reduces prescription drug costs under Medicare Part D. Extra Help covers most or all Part D premiums, eliminates the deductible, and caps copays at a few dollars per prescription.

This automatic enrollment means you do not need to take separate action to get help with prescription costs if you are a full-benefit dual eligible. Your coverage is coordinated between the two programs without requiring you to file additional applications.

Dual Eligible Special Needs Plans (D-SNPs)

What Are D-SNPs?

Dual Eligible Special Needs Plans, known as D-SNPs, offer a tailored way for people with both Medicare and Medicaid to manage their health coverage. These plans bring together benefits from both programs, making it easier to handle doctor visits, prescriptions, and other care needs. Many plans now offer integrated care plans where your Medicare and Medicaid services are managed together by the same plan.

D-SNPs are Medicare Advantage plans designed exclusively for dual-eligible individuals. Unlike standard Medicare Advantage plans that serve both dual-eligible and Medicare-only beneficiaries, D-SNPs work closely with state Medicaid agencies to ensure better coordination of benefits and services. This can simplify your experience by reducing administrative confusion and ensuring your providers have clear information about what each program covers.

Recent Changes to D-SNPs

Plans must now provide one ID card for both Medicare and Medicaid, conduct a single integrated health risk assessment and follow set timelines for creating individualized care plans with input from beneficiaries. These changes improve coordination by consolidating multiple pieces of information into streamlined processes.

Health risk assessments now have formally codified timelines. Plans must complete an initial comprehensive assessment within 90 days of enrollment, covering physical health, social factors, and barriers like housing. This means your plan takes a more comprehensive approach to understanding your healthcare needs and circumstances.

Enrollment and Plan Selection

Enrollment Periods for Dual Eligibles

Enrollment timelines and flexibility have evolved for dual-eligible individuals. Depending on your eligibility, you can now switch plans monthly. In 2025, CMS ended the long-standing special enrollment period (SEP) that previously allowed dual-eligible beneficiaries to switch Medicare Advantage or Part D plans every three months. In its place, CMS created a monthly integrated care SEP, which, in 2026, continues to allow full-benefit beneficiaries to change plans only if they are moving into an integrated D-SNP.

This change means that if you are a full-benefit dual eligible and want to switch plans, you now have the opportunity to do so monthly if you are changing to an integrated D-SNP. If you want to change to a non-integrated plan or are a partial-benefit dual eligible, standard enrollment rules apply. Understanding your enrollment options is important for making informed decisions about your coverage.

Key Takeaways for Finding the Right Plan

• ✅ Compare D-SNP plans available in your ZIP code through Medicare.gov Plan Compare or by calling 1-800-MEDICARE
• ✅ Review what each plan covers under both Medicare and Medicaid to ensure it meets your healthcare needs
• ✅ Consider whether integrated plans, which manage both benefits together, would simplify your care coordination
• ✅ Understand your state's Medicaid coverage rules, as benefits vary by location
• ✅ Speak with a licensed Medicare agent who specializes in dual eligibility if you need personalized guidance

Practical Considerations and Benefits

The combination of both programs covers most or all of your healthcare costs, including premiums, deductibles, copays, and often long-term care. This comprehensive coverage can provide significant financial protection and reduce your out-of-pocket expenses compared to having Medicare alone.

Medicare has significant gaps: it does not cover most dental, vision, hearing, or long-term care. Medicaid fills those gaps for dual eligible individuals. Understanding these complementary benefits helps you make the most of your coverage and access services you might not otherwise afford.

If you have questions about your dual eligibility status, which benefits you qualify for, or how to enroll in a plan, consult with your state Medicaid office, call Medicare directly, or speak with a licensed insurance agent. Your healthcare provider's office can also help answer questions about coverage for specific services. Taking time to understand your options ensures you are using all available benefits to meet your healthcare needs.