CMS Pub. 100-05, ch. 5, § 40.3

When it appears that a GHP should be primary payer, a claim for Medicare primary benefits may not

be processed unless accompanied by an explanation of benefits, or found on the 837 claim, from the

insurer indicating that the GHP has previously processed a claim for the services and denied primary

benefits for reasons other than it makes payment after Medicare for services provided to the

beneficiary.

If the claim is not accompanied by a GHP's explanation of benefits, or the appropriate primary

payment information is not found on the 837 claim, the claim is denied

Unless the claimant submits a satisfactory explanation of why full or partial payment under primary

insurance cannot be made, or in WC, liability, or no-fault claims, there is evidence that a decision

will not be made promptly, the A/B MAC (Part B) denies the claim for primary Medicare benefits.

Medicare is primary only if an insurer that is primary to Medicare cannot make payment. Examples

of acceptable reasons why the GHP cannot pay are:

• A deductible applies, or

• The beneficiary is not entitled to benefits, or

• Benefits under the plan are exhausted for particular services, or

• The services are not covered under the plan.

However, the primary insurer cannot assert that the beneficiary is not entitled to primary benefits or

the services are not covered for primary payment under the plan because the beneficiary has

Medicare.

If the A/B MAC (Part B) pays primary benefits and later learns that the beneficiary is appealing the

GHP's denial, it treats the payment as a conditional primary payment. When a primary Medicare

claim is denied, the denial notice informs the claimant that, after the primary insurer has processed

the claim for primary benefits, a claim for secondary Medicare benefits may be filed and that a copy

of the GHP's explanation of benefits must be included.