1. Insurer obligated to pay losses first when two or more insurers may be responsible for paying the claim. 2. Medicare is a primary payer with respect to Medicaid; for a person eligible under both programs, Medicaid pays only for benefits not covered under Medicare or after Medicare benefits are exhausted. 3. An employer’s health plan if a Medicare patient is covered by that plan, and then Medicare is the secondary payer. 4. Insurance carrier or managed care plan that has the first responsibility under the coordination of benefits clause between two or more insurers.

When coordinating benefits of two insurance plans, the medical expense plan pays benefits first before any benefits are paid by another medical expense plan.

Site where the tumor began or originated.

Patient’s condition established after study that is chiefly responsible for the admission of the patient to the hospital. The principal diagnosis may or may not be the same as the primary diagnosis. Also see admitting diagnosis and major diagnosis .

1. Diagnostic code for a condition established after study that is responsible for the admission of the patient to the hospital. 2. When completing the Uniform Bill (UB-04) paper or electronic claim form, the principal diagnosis code including fourth and fifth digits should appear in Field 67.

Most important medical service performed, usually for treatment, that is related to the chief diagnosis responsible for the admission of the patient to the hospital.

1. ICD-9-CM procedure code for the most important medical service performed, usually for treatment, which is related to the chief diagnosis responsible for the admission of the patient to the hospital. If there are two procedures that are principal, then the one most related to the principal diagnosis should be the principal procedure. 2. When completing the Uniform Bill (UB-04) paper or electronic claim form, the principal procedure code should appear in Field 67. The electronic version requires an eight-character date listing year, month, and day (20XX0425).

The evaluation of a provider request for a specific service to determine the medical necessity and appropriateness of the care requested for a patient. Also called prior authorization in some states.

Group of figures assigned by a managed care plan or insurance program to a specific case after prior approval or precertification for treatment is completed.