Medical Billing and Coding
Billing and coding translate care into payment. Understand the two code systems: ICD-10-CM for diagnoses and CPT/HCPCS for procedures and services, plus modifiers that clarify or adjust a code. Know the revenue cycle in order: registration, coding, charge entry, claim submission, payer adjudication, payment posting, denial management, and patient billing.
Learn the coding basics tested most often: the difference between a new and established patient, evaluation and management levels driven by documented medical decision-making or time, and why the diagnosis must support the procedure billed (medical necessity). Know the common claim forms: CMS-1500 for professional claims and UB-04 for institutional claims. Understand denial reasons such as missing authorization, incorrect modifier, non-covered service, and timely filing limits.
Traps: upcoding (billing a higher level than documented) and unbundling (billing components separately when a bundled code exists) are compliance violations, not shortcuts; assuming a code can be selected without documentation; and forgetting that modifiers change payment, not the underlying diagnosis.
Rule of thumb: code what is documented, and only what is documented. If the note does not support the level, the level is wrong.
Worked example: a note documents a brief problem-focused visit, but the claim uses a high-level E/M code. The correct action is to code to the documented level, not to the higher one.