COC Study Guide 2026
Everything you need to pass the COC exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 COC Exam Format at a Glance
📚 COC Topics to Study (31)
✍️ Sample COC Questions & Answers
1. Which ICD-10-CM convention applies when two conditions are linked by the term 'with' in the Alphabetic Index?
Per ICD-10-CM guidelines, the word 'with' in the Alphabetic Index establishes a presumed relationship that does not require explicit documentation of causation.
2. Modifier -KX is used in Medicare billing to indicate:
Modifier -KX attests that the specific coverage criteria for the billed item or service have been met and that the required documentation is on file.
3. Under the OIG Work Plan, which of the following would be a common audit target for outpatient coding?
The OIG routinely targets providers who bill a disproportionately high frequency of the highest-level E/M codes, which may indicate upcoding.
4. A patient is seen for type 1 diabetes with hypoglycemia with coma. Which ICD-10-CM code is most appropriate?
E10.641 captures type 1 diabetes mellitus with hypoglycemia with coma as a combination code.
5. Which modifier is appended to a CPT code to indicate that a procedure was performed on the right side of the body?
Modifier -RT (Right Side) is used to indicate a procedure was performed on the right side of the body.
6. Which modifier indicates a co-surgery situation where two surgeons perform distinct parts of a procedure simultaneously?
Modifier -62 (Two Surgeons) is used when two surgeons each perform a distinct part of a reportable procedure, each reporting the same CPT code with modifier -62.