COC (Formerly CPC-H) common mistakes
COC (Formerly CPC-H) · Understand the traps and how to avoid them.
Coding the procedure from the report's title, 'Indication,' or the pre-procedure plan instead of the operative/procedure body - e.g., reporting a laparoscopic cholecystectomy for a case documented as 'planned lap chole; converted to open' or 'diagnostic laparoscopy only, no resection performed.'
Time pressure makes candidates skim the first two lines of an operative note; the title reflects intent, not what was performed, and converted, aborted, and diagnostic-only cases are exactly where the body of the report changes the code.
What to do instead
Read the entire note, specifically the 'findings,' 'procedure performed,' and closing paragraphs. Code what was actually done, capture the approach and any conversion, and confirm units and laterality against the body text before selecting the CPT code.
Sequencing the final or definitive diagnosis as first-listed on an outpatient/same-day-surgery claim, or coding a 'probable,' 'suspected,' or 'rule out' condition that is still pending workup.
Candidates carry inpatient principal-diagnosis habits into the outpatient record. Outpatient first-listed diagnosis is the condition chiefly responsible for the encounter as documented at the time of service, and uncertain diagnoses are not reportable in the outpatient setting.
What to do instead
Ask 'what was the reason for this encounter today?' If the workup is inconclusive, code the signs and symptoms that prompted the service and add any confirmed secondary diagnoses. Never assign an uncertain diagnosis on an outpatient claim.
Choosing a code from the alphabetic index and stopping there, skipping the tabular notes: missing a required additional code ('code also'), misreading Excludes1 as Excludes2, dropping the 7th character, or leaving off laterality.
Index entries point to a code family but do not carry the full instructional notes; answer options are deliberately built around the difference between the valid complete code and its truncated or wrongly-sequenced neighbour.
What to do instead
After locating the code in the index, always verify it in the tabular list at the category and code level. Check every note (includes, excludes1/excludes2, code first/code also, use additional code), verify laterality and encounter-specific 7th characters, and confirm the code is valid for billing (not a 'code not otherwise specified' left truncated).
Coding a diagnosis that appears only in a preliminary or provisional note, an unsigned addendum, or a pending pathology/lab result that had not been interpreted at the time of code assignment.
Candidates want the 'best' or most specific diagnosis and pull it from wherever it appears, but documentation that is not final, authenticated, or available at the time of coding cannot support a code.
What to do instead
Code only from authenticated, final documentation. If the result is pending, code the sign/symptom or the documented working condition as allowed, and issue a compliant query if clarification is needed for the record; do not code forward from an anticipated result.
Selecting a diagnosis or procedure based on what will 'support payment' rather than what the documentation states - picking a high-severity secondary diagnosis from the patient's history list, or upcoding a service to match a payable APC.
Revenue-cycle pressure and familiarity with payer edits tempt candidates to reverse-engineer the code from the payment outcome instead of the record, which is both a coding error and a compliance exposure.
What to do instead
Code strictly from the documentation, then check the claim result. If medical necessity or APC assignment looks inadequate, the remedy is a physician query or a corrected charge description master mapping, never a change to the code without supporting documentation.
Carrying the physician global surgical package and physician E/M leveling logic into hospital outpatient same-day surgery: deciding E/M levels by MDM, bundling post-operative visits into the surgical code, or expecting the surgeon's professional-fee rules to apply to the facility claim.
Most study material and real-world experience is physician-side; candidates assume the same rules govern the facility record, but the hospital reports the facility component of the service with its own code sets and payment logic.
What to do instead
Separate the two claims in your mind. On the facility side, assign facility E/M levels using the hospital's facility leveling criteria and report the facility resources actually provided. Do not apply the physician global period to facility reporting decisions.
Mishandling observation: not reconciling the documented observation hours against the units reported, omitting the observation HCPCS reporting, or failing to recognize when the record documents an inpatient admission that changes the reporting.
Observation is time-based and documented by nursing flowsheets that candidates rarely read in full; the admission-to-discharge interval and the order status are easy to skim past.
What to do instead
Read the observation order and the nursing time record. Compute hours from the observation start to discharge, report the observation service in the required hourly increments consistent with the record, and verify whether an inpatient order exists that supersedes observation reporting.
Assigning emergency department facility levels by copying the physician's MDM-based E/M level, or defaulting to the highest/lowest ED code instead of applying the hospital's own ED leveling criteria.
The physician and facility ED levels are determined by different criteria and may legitimately differ on the same encounter; candidates equate the two and assume one level fits both claims.
What to do instead
Apply the facility's ED leveling tool (based on hospital resources, interventions, and staff effort documented by nursing and ancillary staff) to the facility record, and treat the physician's professional level as a separate determination.
Missing endoscopy and multiple-procedure logic: reporting each endoscopy at full value without applying CPT multiple-procedure guidance and the appropriate modifier, and sequencing the screening diagnosis as first-listed when the procedure became diagnostic and a therapeutic intervention was performed.
Endoscopy notes document several scopes and interventions in one session, and candidates report them line-by-line from the report body without mapping them to the code families, 'with' relationships, and reduction rules that govern combined reporting.
What to do instead
Identify each procedure family, use the CPT 'with' relationships to avoid reporting an included service separately, reduce secondary procedures per the payer's multiple-procedure rules with the correct modifier, and set the first-listed diagnosis to reflect the reason the procedure was ultimately performed (for example, the finding that converted a screening to a diagnostic/therapeutic service).
Mismatching HCPCS/CPT lines to revenue codes and separately billing services the OPPS packages - for example, putting a procedure in a clinic revenue code instead of the surgical suite code, or billing a packaged supply, routine lab, or status-indicator 'N' item as its own payable line.
Candidates learn the code sets but not the charge-mapping layer, so the procedure code is correct while the UB-04 line assignment and APC grouping are wrong, producing payment differences and edits that look like coding errors.
What to do instead
For every line, confirm three things: the correct revenue code for where and what the service is, the HCPCS/CPT that maps to it, and the OPPS status indicator. Do not bill packaged items separately; validate the mapping against the charge description master and the current OPPS additive/packaging files.