CRCR Coordination of Benefits (COB) and Secondary Billing — Questions and Answers
Question 1: A patient is covered by both their own employer's plan and their spouse's employer plan. The 'birthday rule' is used to determine:
- Which plan is primary based on whose birthday falls earlier in the calendar year (Correct answer)
- Which plan covers the patient based on the date of their original enrollment
- The order of liability based on the patient's age relative to their spouse
- Which plan applies a deductible first when both plans have equal coverage
Correct answer: Which plan is primary based on whose birthday falls earlier in the calendar year
The birthday rule states that when a patient is covered by two plans, the plan of the policyholder whose birthday (month and day) falls earlier in the calendar year is primary. Year of birth is not used unless birthdays fall on the same day.
Question 2: Under Medicare Secondary Payer (MSP) rules, Medicare is the SECONDARY payer when:
- The patient is actively employed and covered by an employer group health plan from an employer with 20 or more employees (Correct answer)
- The patient is enrolled in both Medicare Part A and Part B simultaneously
- The patient's primary diagnosis is a chronic condition such as diabetes or hypertension
- The patient receives services at a Critical Access Hospital
Correct answer: The patient is actively employed and covered by an employer group health plan from an employer with 20 or more employees
MSP rules require that an employer group health plan (EGHP) from an employer with ≥20 employees pays primary when the Medicare beneficiary is actively working and covered under the EGHP. Medicare only pays secondary in that scenario.
Question 3: What is 'crossover billing' in the context of coordination of benefits?
- The process where Medicare automatically forwards a claim to Medicaid for beneficiaries who are dual-eligible, so the provider does not need to bill Medicaid separately (Correct answer)
- Submitting the same claim to two commercial payers simultaneously to maximize reimbursement
- Transferring an unpaid balance from a primary insurer to the patient's self-pay account
- Re-coding a denied claim with an alternate procedure code before secondary submission
Correct answer: The process where Medicare automatically forwards a claim to Medicaid for beneficiaries who are dual-eligible, so the provider does not need to bill Medicaid separately
For dual-eligible patients (Medicare and Medicaid), Medicare electronically 'crosses over' the claim to Medicaid after adjudication, so the provider receives both Medicare payment and any Medicaid supplemental payment without filing a separate Medicaid claim.
Question 4: When billing a secondary payer, the amount submitted should be based on:
- The remaining balance after the primary payer's payment and any contractual adjustments have been applied (Correct answer)
- The provider's full billed charges, regardless of what the primary payer paid
- The secondary payer's own allowed amount for the service independent of the primary payer's adjudication
- The patient's annual deductible divided equally between both payers
Correct answer: The remaining balance after the primary payer's payment and any contractual adjustments have been applied
Secondary billing is based on the patient's remaining liability after the primary payer adjudicates the claim. The secondary payer's Explanation of Benefits (EOB/RA) from the primary must accompany the claim to show what was paid and what remains.
Question 5: A COB clause in a health insurance policy is designed primarily to:
- Prevent a patient from collecting more than 100% of the allowable amount for a service when covered by multiple insurance plans (Correct answer)
- Allow the insurer to deny claims if the provider fails to obtain prior authorization
- Require that all providers in the network accept assignment of benefits
- Establish the patient's right to appeal claim denials to an independent review organization
Correct answer: Prevent a patient from collecting more than 100% of the allowable amount for a service when covered by multiple insurance plans
Coordination of benefits rules exist to ensure that when a patient has multiple health plans, the combined payment from all payers does not exceed the total allowed amount or the provider's billed charge — preventing over-payment or patient profit.
Question 6: Which of the following situations correctly identifies Medicare as the PRIMARY payer?
- A Medicare beneficiary who has end-stage renal disease (ESRD) and is in the 31st month of their coordination period (Correct answer)
- A 68-year-old Medicare beneficiary currently employed full-time at a company with 25 employees
- A Medicare beneficiary injured in a motor vehicle accident where auto liability insurance applies
- A Medicare beneficiary covered under a working spouse's large-group employer plan
Correct answer: A Medicare beneficiary who has end-stage renal disease (ESRD) and is in the 31st month of their coordination period
For ESRD patients, the group health plan is primary for the first 30 months (the coordination period); after that period ends, Medicare becomes primary. Options B, C, and D all represent situations where Medicare is secondary under MSP rules.
CRCR Coordination of Benefits (COB) and Secondary Billing
A patient is covered by both their own employer's plan and their spouse's employer plan.
The 'birthday rule' is used to determine: