COC Cheat Sheet 2026

The 30 highest-yield COC facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What does the prefix 'sub-' mean? → below or under
2. A patient is treated for cellulitis of the right lower leg caused by Staphylococcus aureus. How many ICD-10-CM codes are required? → Two codes: L03.115 for right lower leg cellulitis and B95.61 for MSSA
3. Which modifier is appended to a CPT code to indicate a bilateral procedure? → -50
4. Which of the following best describes 'medical necessity' in coding compliance? → Services must be appropriate to the diagnosis, evidence-based, and not excessive
5. The prefix 'tachy-' means: → rapid
6. Which modifier indicates that a service or procedure has been reduced or eliminated at the physician's discretion? → -52
7. Which modifier is appended to a CPT code to indicate that a procedure was performed on the right side of the body? → -RT
8. Which ICD-10-CM chapter contains codes for external causes of morbidity? → Chapter 20 (V00–Y99)
9. What is the purpose of CPT modifier -59? → Distinct procedural service not normally reported together
10. Modifier -76 is used to report: → Repeat procedure by the same physician
11. Category III CPT codes are used for: → Emerging technology, services, and procedures
12. Which CPT modifier indicates a service was reduced or eliminated at the physician's discretion? → -52
13. The combining form 'pneumo-' refers to: → lung
14. The suffix '-plasty' means: → surgical repair
15. A patient is diagnosed with deep vein thrombosis (DVT) of the popliteal vein. The popliteal vein is located in which body region? → Behind the knee
16. Modifier -57 is used when an E/M service results in the initial decision to perform: → A major surgery (90-day global)
17. A patient receives 250 mg of a drug, but the HCPCS code describes 50 mg per unit. How many units are reported? → 5
18. The prefix 'ante-' means: → before or in front of
19. A patient is seen in the ED for acute exacerbation of COPD with acute bronchitis. How should these conditions be coded? → Code the combination code J44.0 (COPD with acute lower respiratory infection)
20. What is the 'clean claim' in the context of the revenue cycle? → A claim submitted without errors that requires no additional information for payment
21. When ICD-10-CM documentation states 'due to' or 'secondary to' within the medical record, this typically indicates: → A cause-and-effect relationship requiring a combination or linked code
22. The combining form 'osteo-' relates to: → bone
23. A provider routinely waives patient copayments and deductibles without hardship assessment. This is considered: → Fraudulent — it misrepresents the actual charge and can induce overutilization
24. Which term describes billing for services NOT actually rendered? → Phantom billing (fraud)
25. In CPT coding, an 'unlisted procedure' code is used when: → No specific CPT code adequately describes the service performed
26. A choledochal cyst is a cyst originating from which structure? → common bile duct
27. Which letter begins HCPCS Level II codes for durable medical equipment (DME)? → E
28. When two or more physicians each perform a portion of a surgical team procedure, the appropriate modifier is: → -66
29. Which structure of the heart is responsible for initiating the electrical impulse that triggers each heartbeat? → Sinoatrial (SA) node
30. Which federal program monitors healthcare claims for fraud, waste, and abuse through data analysis and audits? → Recovery Audit Contractor (RAC) Program