Medicare Secondary Payer

Medicare Secondary Payer (MSP) is the term generally used when the Medicare program does not have primary payment responsibility - that is, when another entity has the responsibility for paying before Medicare. When Medicare began in 1966, it was the primary payer for all claims except for those covered by Workers' Compensation, Federal Black Lung benefits, and Veteran’s Administration (VA) benefits.

In 1980, Congress passed legislation that made Medicare the secondary payer to certain primary plans in an effort to shift costs from Medicare to the appropriate private sources of payment. The MSP provisions have protected Medicare Trust Funds by ensuring that Medicare does not pay for items and services that certain health insurance or coverage is primarily responsible for paying. The MSP provisions apply to situations when Medicare is not the beneficiary’s primary health insurance coverage. Medicare statute and regulations require that all entities that bill Medicare for items or services rendered to Medicare beneficiaries must determine whether Medicare is the primary payer for those items or services.

Primary payers are those that have the primary responsibility for paying a claim. Medicare remains the primary payer for beneficiaries who are not covered by other types of health insurance or coverage. Medicare is also the primary payer in certain instances, provided several conditions are met.

CMS has made available a curriculum of computer-based training (CBT) courses that will assist you in understanding the fundamentals of MSP. You can access or download these CBTs from the Downloads section below. The first item listed is the MSP Curriculum document that contains a complete listing of the courses, their descriptions, and course lengths.

Common Situations of Primary vs. Secondary Payer Responsibility

The following list identifies some common situations when Medicare and other health insurance or coverage may be present, and which entity will be the primary or secondary payer.

1. Working Aged (Medicare beneficiaries age 65 or older) and Employer Group Health Plan (GHP):

2. Disability and Employer GHP:

3. End-Stage Renal Disease (ESRD) :

Please see the ESRD page for more information.

4. Consolidated Omnibus Budget Reconciliation Act of 1985 (COBRA) – the law that provides continuing coverage of group health benefits to employees and their families upon the occurrence of certain qualifying events where such coverage would otherwise be terminated.


5. Retiree Health Plans

6. No-fault Insurance and Liability Insurance

7. Workers’ Compensation Insurance

Note: When there is evidence that the no-fault insurer, liability insurer, or workers’ compensation plan will not pay promptly, Medicare may make a conditional payment. A conditional payment is a payment Medicare makes for services another payer may be responsible for. Medicare makes this conditional payment so that the beneficiary won’t have to use his own money to pay the bill. The payment is “conditional” because it must be repaid to Medicare when a settlement, judgment, award or other payment is made.

Federal law takes precedence over state laws and private contracts. Even if an entity believes that it is the secondary payer to Medicare due to state law or the contents of its insurance policy, the MSP provisions would apply when billing for services.

Responsibilities of Beneficiaries Under MSP

As a beneficiary, we advise you to:

Please select Beneficiary Services in the Related Links section below for more information.

Responsibilities of Providers Under MSP

As a Part A institutional provider (i.e., hospitals), you should:

As a Part B provider (i.e., physicians and suppliers), you should:

Please select Provider Services in the Related Links section below for more information.

Responsibilities of Employers Under MSP

As an employer, you must:

Please select Employer Services in the Related Links section below for more information.

Statutory and regulatory provisions

The information above provides only a very high-level overview of the MSP provisions. See 42 U.S.C. 1395y(b) [section 1862(b) of the Social Security Act], and 42 C.F.R. Part 411, for the applicable statutory and regulatory provisions.