COC Exam Study Tips: Domain-by-Domain Prep Strategies

CPT & HCPCS Coding for Outpatient Procedures (35%)

• Learn modifier usage in outpatient-specific contexts, not just generic definitions — practice applying modifiers like -25, -59, -76, -78, and -79 to realistic outpatient scenarios.
• Review NCCI edits and Medically Unlikely Edits (MUEs) and understand how they prevent improper code combinations from being billed together.
• Study global surgical package rules carefully, including what's bundled into the global period and what can be billed separately.
• Practice distinguishing separately payable procedures from bundled/packaged ones, since this distinction underlies much of outpatient coding logic.

ICD-10-CM Diagnosis Coding (25%)

• Memorize the outpatient-specific rule against coding uncertain diagnoses ("rule out," "probable," "suspected") as if confirmed — this is one of the most frequently tested outpatient-specific coding rules.
• Practice using the Alphabetic Index and Tabular List together, always verifying in the Tabular List before finalizing a code.
• Learn excludes1 versus excludes2 notes precisely — excludes1 means the two conditions can never be coded together, while excludes2 means they can coexist and both may be coded.
• Review the seventh-character extension rules for injury and certain other code categories, including the distinction between initial encounter, subsequent encounter, and sequela.

Outpatient Facility Billing & Reimbursement (20%)

• Learn the OPPS/APC system from the ground up, especially if your background is physician-office coding — this content has no direct physician-fee equivalent.
• Understand status indicators and what they mean for payment — separately payable, packaged, and other designations directly affect how a claim is reimbursed.
• Know the difference between OPPS and the ASC payment system, since they apply to different facility types with different rate structures.
• Review the UB-04 claim form's key fields — revenue codes, condition codes, and occurrence codes — since facility billing uses a different claim form than physician-office billing.

Medical Terminology, Anatomy & Compliance (20%)

• Drill prefixes, suffixes, and directional terms as flashcards — this is fast, high-value review that pays off across all the coding-heavy domains too.
• Review major body systems and their key structures, since accurate code selection depends on correctly interpreting anatomical documentation.
• Understand compliance basics relevant to coding accuracy, including upcoding risk and the False Claims Act's relevance to knowingly inaccurate coding.

General Strategy: Practice With Realistic Scenarios

Because COC questions are frequently scenario-based rather than pure definition recall, practice reading brief clinical descriptions and determining the correct code — this mirrors the actual exam format far better than reviewing code lists in isolation.

Put These Tips Into Practice

Our COC exam page has free practice quizzes broken out by domain, plus a full mock exam, to help you target your remaining study time.