Dual-Eligible Beneficiary
A dual-eligible beneficiary qualifies for both Medicare and Medicaid. Medicare pays first as primary; Medicaid pays second, covering Medicare cost sharing and services Medicare excludes. For most dual-eligibles, providers cannot balance-bill the patient for Medicare deductibles or coinsurance, a rule that catches many billing teams.
- Coverage
- Both Medicare and Medicaid
- Payment order
- Medicare primary, Medicaid secondary
- Balance billing
- Prohibited for QMB cost sharing
- Claim flow
- Often crosses over automatically
What is a dual-eligible beneficiary?
A dual-eligible beneficiary is enrolled in both Medicare and Medicaid. Medicare covers the medical benefits; Medicaid steps in as a payer of last resort for cost sharing and, for full-benefit duals, services Medicare does not cover such as long-term care. Duals are among the most complex patients to bill correctly because two government programs coordinate on every claim.
They divide into full-benefit duals with comprehensive Medicaid and partial duals whose Medicaid help is limited to premiums and cost sharing.
How do Medicare and Medicaid coordinate for duals?
Medicare always pays first. The claim then flows to Medicaid as secondary through coordination of benefits. This is the opposite of a Medicare Secondary Payer situation, where a commercial plan pays before Medicare.
| Step | Payer |
|---|---|
| Primary adjudication | Medicare (Part A/B) |
| Secondary adjudication | State Medicaid |
| Remaining balance | Not billable to QMB patient |
Why can't you bill dual-eligible patients for coinsurance?
Example: a QMB patient has a $500 Medicare-allowed visit. Medicare pays 80 percent, leaving $100 coinsurance plus any deductible. You bill Medicaid, which pays nothing because its rate is below what Medicare already paid. Federal QMB rules still forbid billing the patient the $100, so it is written off, not collected.
Frequently asked questions
Someone who qualifies for both Medicare (usually by age or disability) and Medicaid (by income and assets). Duals split into full-benefit duals, who get comprehensive Medicaid, and partial duals, whose Medicaid help is limited to Medicare premiums and cost sharing through Medicare Savings Programs like QMB.
Generally no. For Qualified Medicare Beneficiary (QMB) individuals, federal law bars providers from balance-billing the patient for Medicare deductibles, coinsurance, or copays. You bill Medicaid for that cost sharing and accept its payment, even when Medicaid pays little or nothing. Billing the QMB patient anyway is a compliance violation.
Medicare adjudicates first as primary. The claim then crosses over to Medicaid, which pays secondary toward the remaining cost sharing up to the Medicaid allowable. Because state Medicaid rates are often lower than Medicare's, the secondary payment is frequently zero, yet the patient still cannot be billed the difference.
Sources & further reading
Reviewed by the ImmediCare Solutions RCM team
Certified billers and coders handling claims across 50+ specialties nationwide. This entry is reviewed against current payer policy and CMS rules. Last review: Jul 5, 2026.
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