Medicaid vs. Medicare
Medicaid and Medicare are separate United States public health-coverage programs that are frequently confused because their names are similar and some people qualify for both. Medicare is a federal program administered by the Centers for Medicare & Medicaid Services that primarily serves people aged 65 and older and certain younger people with qualifying conditions, with eligibility and core rules set at the national level. Medicaid is jointly funded by federal and state governments and administered by each state within federal guidelines, so eligibility, covered benefits, and payment rules vary by jurisdiction. For billing and revenue-cycle staff, the practical consequences show up in provider enrollment, claim routing, timely-filing windows, and coordination of benefits. The specific figures, thresholds, and covered services differ by program, plan, state, and date, so this article describes structure rather than quoting any single rule as universal.
Updated 7 min read
Reviewed by Anwaar Tayyab
Director of Billing Operations ·
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Key takeaways
- Medicare is federally administered with largely national rules; Medicaid is administered by each state within federal guidelines, so its rules vary by jurisdiction.
- Eligibility bases differ: Medicare is tied mainly to age and certain qualifying conditions, while Medicaid is tied primarily to household income and to categorical eligibility groups, with each state electing which optional groups to cover within federal rules.
- Enrollment pathways are separate: Medicare uses PECOS online or the paper CMS-855 application family, while Medicaid enrollment runs through each state's Medicaid agency or its designated system.
- Some individuals qualify for both programs (dual-eligible), which triggers specific coordination-of-benefits and crossover-claim handling.
- Because covered services, fee schedules, prior-authorization rules, and timely-filing windows differ by program and jurisdiction, billing staff should verify current requirements against authoritative sources rather than assume one program's rules apply to the other.
The core structural difference
The most consequential difference between the two programs is how they are governed. Medicare is a federal program: its structure, eligibility categories, and core payment methodologies are established nationally, and it is administered through the Centers for Medicare & Medicaid Services and its contractors. Medicaid, by contrast, is a partnership. It is jointly funded by the federal government and the states and is administered by each state within federal minimum requirements. States have latitude to set many eligibility rules, cover optional benefits, and design their own delivery systems, which is why Medicaid rules differ from one state to another.
That governance split explains most downstream billing differences. A single national rule set makes Medicare comparatively uniform across the country, whereas Medicaid requires staff to confirm requirements for the specific state program in which a beneficiary is enrolled. Neither program is monolithic, though: both are delivered partly through private managed-care and Medicare Advantage plans that add their own contractual layers.
Variation is the rule, not the exception
Eligibility and funding compared
The two programs reach different populations. Medicare eligibility is tied mainly to age and to certain qualifying conditions rather than to income. Medicaid eligibility is tied primarily to household income and to categorical eligibility groups, with each state electing which optional groups to cover within federal rules, which is why Medicaid populations and thresholds differ across jurisdictions. Related to Medicaid, the Children's Health Insurance Program (CHIP) covers certain children in families with incomes above Medicaid limits, and states administer CHIP alongside Medicaid in various models.
| Dimension | Medicare | Medicaid |
|---|---|---|
| Administration | Federal, through CMS and its contractors | State-administered within federal guidelines |
| Funding | Primarily federal | Jointly funded by federal and state governments |
| Primary eligibility basis | Age and certain qualifying conditions | Household income and categorical groups, including state-elected optional groups |
| Rule uniformity | Largely national | Varies by state |
| Provider enrollment path | PECOS online or the paper CMS-855 application family | State Medicaid agency or its designated system |
Dimensions are structural; the underlying specifics vary by program, plan, state, and date.
Confirming which program applies, and whether a beneficiary is enrolled in a managed plan, is a front-end eligibility verification task. Guidance for each program is covered separately in verifying Medicaid coverage and in the broader eligibility verification category.
Delivery systems and payment
Both programs deliver benefits through more than one arrangement. Traditional Medicare pays claims on a fee-for-service basis through administrative contractors, while Medicare Advantage plans provide benefits through private insurers. Medicaid similarly operates through fee-for-service and managed care, with many beneficiaries enrolled in a managed care organization that contracts with the state.
Payment methodologies differ between and within the programs. Medicare publishes national fee schedules developed by CMS, while Medicaid reimbursement is set by each state and its plans and is not uniform nationally. As a result, allowed amounts, prior authorization requirements, and covered-service lists must be checked against the applicable program, plan, and state policy rather than assumed.
A distinctive Medicaid benefit
Claims, enrollment, and timely filing
Provider enrollment is program-specific. Medicare enrollment runs through PECOS, the online Medicare enrollment system, or the corresponding paper CMS-855 application family, while Medicaid enrollment is handled by each state's Medicaid agency or its designated system. Both are distinct from credentialing, which payers and plans perform separately.
Claim submission uses the same standard formats across payers, generally the CMS-1500 for professional services and the UB-04 for institutional services, but the routing, edits, and adjudication rules differ by program and plan. Timely filing differs in how the window is set rather than in whether a federal limit exists: Medicare timely filing is fixed nationally by federal regulation, while Medicaid timely filing is set by each state inside a federal outer limit that every state must impose on providers.
- Verify which program and plan is active before service, since managed enrollment changes routing and prior-authorization rules.
- Match the claim form and enrollment record to the correct program and rendering arrangement.
- Confirm the applicable timely-filing window for the specific payer, because a state's window can be shorter than the federal outer limit.
- Track program-specific denial reasons; see common Medicaid billing denials for Medicaid-side patterns.
When both programs apply
Some individuals qualify for both Medicare and Medicaid. These dual-eligible beneficiaries trigger specific coordination rules because the two programs pay in a defined order. In this arrangement Medicare generally pays first for Medicare-covered services and Medicaid functions as the payer of last resort, covering certain remaining amounts according to state rules.
Operationally, this often involves crossover claims, in which a processed Medicare claim is forwarded for secondary Medicaid consideration, and it interacts with Medicaid third-party liability rules. The exact amounts Medicaid pays on dual claims, and the conditions for payment, are governed by each state and can change, so current state policy should be confirmed rather than generalized from another jurisdiction.
Do not assume symmetry
Frequently asked questions
Is Medicare or Medicaid administered by the federal government?
Medicare is a federal program administered through the Centers for Medicare & Medicaid Services. Medicaid is jointly funded by federal and state governments and administered by each state within federal guidelines, which is why Medicaid rules vary by jurisdiction while Medicare rules are largely national.
Can a person have both Medicare and Medicaid?
Yes. Individuals who qualify for both are described as dual-eligible. In that situation Medicare generally pays first for Medicare-covered services and Medicaid acts as the payer of last resort, subject to each state's rules. This arrangement often involves crossover claims and coordination-of-benefits handling.
Do Medicare and Medicaid use different provider enrollment systems?
Yes. Medicare enrollment is processed through PECOS, the online Medicare enrollment system, or the corresponding paper CMS-855 application family, while Medicaid enrollment is handled by each state's Medicaid agency or its designated system. Enrollment in one program does not enroll a provider in the other, and both are distinct from payer credentialing.
Are timely-filing deadlines the same for both programs?
Not in the way they are set. Medicare's filing deadline is fixed nationally by federal regulation, while each state Medicaid agency sets its own provider filing requirement inside a federal outer limit. Staff should confirm the applicable window for the specific program, plan, and state rather than applying one program's deadline to the other.
Do the two programs cover the same services?
Not necessarily. The programs serve different core populations and set benefits differently. Medicaid includes benefits such as EPSDT for eligible children that have no direct Medicare equivalent, and Medicaid covered services vary by state. Covered-service lists should be verified for the applicable program, plan, and jurisdiction.
Related glossary terms
Key terms that recur when comparing and billing the two programs.
Related reading
Continue with these related articles in the Medicaid billing cluster.
How Medicaid works
An overview of Medicaid's federal-state structure, administration, and delivery systems.
Fee-for-service vs. managed Medicaid
How the two Medicaid delivery models differ for routing, authorization, and payment.
Dual-eligible beneficiaries
How claims are handled for people covered by both Medicare and Medicaid.
The federal-state structure of Medicaid
Why Medicaid rules vary by state and how federal guidelines set the floor.
Medicaid crossover claims
How processed Medicare claims are forwarded for secondary Medicaid consideration.
Authoritative sources
- 42 U.S.C. § 1395c — Description of program (opens in a new tab)
United States Code, 2023 Edition (GPO). Sets out who the federal Medicare hospital insurance program covers: individuals age 65 or over who are eligible for retirement benefits under Social Security or the railroad retirement system, individuals under 65 entitled for a sustained period to benefits on the basis of a disability, and certain individuals medically determined to have end stage renal disease — the age-and-condition basis that distinguishes Medicare eligibility from Medicaid's income and categorical tests.
- 42 CFR 431.10 — Single State agency (opens in a new tab)
eCFR. Requires a Medicaid State plan to specify a single State agency established or designated to administer or supervise the administration of the plan, to certify that agency's legal authority to make binding rules, and to place responsibility for determining eligibility for all applicants and beneficiaries with it — the provision that makes Medicaid state-administered rather than federally administered.
- 42 CFR 433.10 — Rates of FFP for program services (opens in a new tab)
eCFR. Describes the Federal medical assistance percentage (FMAP), under which the federal government pays a state for part of its expenditures for services under an approved Medicaid State plan, with the federal share rising or falling against the state's per capita income between a statutory floor and ceiling — the mechanism behind Medicaid's joint federal-state funding.
- 42 CFR 435.603 — Application of modified adjusted gross income (MAGI) (opens in a new tab)
eCFR. Makes household income the financial test for Medicaid: the agency must apply the modified adjusted gross income (MAGI) financial methodologies set out in this section in determining the financial eligibility of all individuals for Medicaid, apart from the groups the section expressly excepts, and it defines the household whose income is counted.
- 42 CFR 435.201 — Individuals included in optional groups (opens in a new tab)
eCFR. Shows where state latitude over Medicaid's categorical groups sits: a state agency may choose to cover as optional categorically needy any of the listed groups — aged individuals, blind individuals, disabled individuals, individuals under a specified age or reasonable classifications of them, and parents and other caretaker relatives — and if it covers a group it must cover everyone who applies and is found eligible for that group.
- 42 CFR 457.310 — Targeted low-income child (opens in a new tab)
eCFR. Defines the child CHIP is built to cover, including a child living in a state that has a Medicaid applicable income level whose household income exceeds that level for the child's age by no more than a capped number of percentage points, and who has not been found eligible or potentially eligible for Medicaid — the above-Medicaid-limits position CHIP occupies relative to Medicaid.
- Fee Schedules — General Information (opens in a new tab)
Centers for Medicare & Medicaid Services. States that a fee schedule is a complete listing of fees used by Medicare to pay doctors or other providers and suppliers, applied to reimburse them on a fee-for-service basis, and that CMS develops fee schedules for physicians, ambulance services, clinical laboratory services, and durable medical equipment, prosthetics, orthotics, and supplies — the nationally published Medicare pricing contrasted here with state-by-state Medicaid reimbursement.
- Medicare Enrollment Applications (opens in a new tab)
Centers for Medicare & Medicaid Services. CMS's provider and supplier enrollment page: providers may enroll online through PECOS, the internet-based Medicare enrollment management system, or on the paper CMS-855A, CMS-855B, CMS-855I, CMS-855O, and CMS-855S forms, which are used for initial enrollment, revalidation, changes in status, and voluntary termination, and are filed with a Medicare Administrative Contractor, except the CMS-855S, which DMEPOS suppliers file with the National Provider Enrollment DMEPOS East or West contractor.
- 42 CFR 455.410 — Enrollment and screening of providers (opens in a new tab)
eCFR. Places Medicaid provider enrollment with the state: the State Medicaid agency must require all enrolled providers to be screened and must require ordering or referring physicians and other professionals furnishing services under the State plan or a waiver to be enrolled as participating providers, and it may rely on screening already performed by Medicare contractors or by another state's Medicaid or CHIP program.
- National Uniform Claim Committee — 1500 Claim Form (opens in a new tab)
National Uniform Claim Committee. The committee that maintains the professional paper claim form known in billing practice as the CMS-1500 describes it as a single paper claim form for use by all third-party payers, developed out of the Uniform Claim Form Task Force co-chaired by the American Medical Association and CMS, with the current Version 02/12 of the form in effect since 2014.
- National Uniform Billing Committee — Official UB-04 Data Specifications Manual (opens in a new tab)
National Uniform Billing Committee (American Hospital Association). Explains that the Official UB-04 Data Specifications Manual is the only official source of UB-04 billing information adopted by the NUBC, that it carries the data elements and codes used on the UB-04 claim form and in the electronic HIPAA institutional 837 health care claim transaction standard, and that the NUBC — chaired by the AHA with national provider and payer representation — approves the form's design and its updates. The manual itself is copyrighted and available only by subscription or license.
- 42 CFR 424.44 — Time limits for filing claims (opens in a new tab)
eCFR. Fixes the Medicare claim filing deadline nationally by regulation, measured from the date of service, and lists the narrow circumstances in which CMS or a contractor may extend it — including retroactive Medicare entitlement and recovery of a payment by a state Medicaid agency or a Medicare Advantage organization.
- 42 CFR 447.45 — Timely claims payment (opens in a new tab)
eCFR. Paragraph (d)(1) requires the Medicaid agency to make providers submit all claims within an outer period measured from the date of service, so a state's own filing window sits inside a federal limit rather than being set freely; paragraph (d)(4)(ii) sets a separate allowance for a Medicaid claim relating to services already claimed under Medicare, running from notice of the Medicare disposition.
- 42 CFR 433.139 — Payment of claims (opens in a new tab)
eCFR. Sets how a state Medicaid agency handles claims involving third party liability: where probable liability is established when the claim is filed, the agency must reject the claim and return it to the provider for a determination of the amount of liability, then pay only to the extent the amount allowed under its own payment schedule exceeds the third party's payment — the residual position described as Medicaid being the payer of last resort.