Reimbursement and Basic Coding
Reimbursement content tests the revenue cycle from registration through payment. Know the payer mix-Medicare, Medicaid, commercial, managed care, workers' compensation, and self-pay-and the cost-sharing terms: deductible, copayment, coinsurance, and out-of-pocket maximum. Fee-for-service pays per service; capitation pays a fixed amount per member per period; bundled or value-based models tie payment to quality and outcomes.
Coding uses ICD-10-CM for diagnoses, ICD-10-PCS for inpatient procedures, CPT for outpatient professional services, and HCPCS Level II for supplies, drugs, and some services. The claim form matters: CMS-1500 is used for professional claims, UB-04 for institutional claims. Medical necessity links the diagnosis to the service; lack of medical necessity is a common denial reason. Modifiers explain unusual circumstances, such as a distinct service (modifier 25) or a separately identifiable procedure (modifier 59), but they must be supported by documentation. National Correct Coding Initiative (NCCI) edits prevent unbundling. Clean claims require accurate demographics, insurance, coding, and timely filing.
Common traps: coding from the order or from memory rather than the provider's documentation; using an inpatient procedure code on an outpatient claim; missing prior authorization; and ignoring the explanation of benefits (EOB) or electronic remittance advice (ERA). Denials should be worked by category: eligibility, authorization, coding, medical necessity, or timely filing.
Worked example: A provider documents a problem-focused visit and orders labs. The coder selects an evaluation and management code based on the documented history, exam, and medical decision making-not on the lab order. If the documentation does not support the level, query the provider or code lower.
Rule of thumb: Code what is documented, not what you assume was done.