COC (Formerly CPC-H) cheat sheet

ICD-10-CM diagnosis codes contain 3–7 characters; a 7th character is required in categories such as injuries and obstetrics and identifies encounter type (A initial, D subsequent, S sequela).

CPT Category I codes are five digits; Category III codes are four digits plus T; HCPCS Level II codes are one letter plus four digits.

For hospital outpatient facility claims, report ICD-10-CM diagnoses and CPT/HCPCS procedures/services; ICD-10-PCS is used for inpatient procedure reporting, not outpatient.

The outpatient principal/first-listed diagnosis is the condition chiefly responsible for the encounter after study; do not code uncertain “rule-out” diagnoses as confirmed in outpatient.

Modifier 25 reports a significant, separately identifiable E/M service on the same day as a procedure; documentation must support a service beyond the procedure’s usual pre/post work.

Distinct procedural service modifiers include 59 and XE, XP, XS, XU; use only when no more specific modifier explains the distinct service and documentation supports it.

NCCI procedure-to-procedure edits pair a column 1 code with a column 2 code; override a PTP edit only with an appropriate modifier and clinical documentation.

Add-on CPT codes are billed with their primary procedure, are not reported alone, and generally are exempt from modifier 51 multiple-procedure reduction.

HCPCS Level II J-codes report drug dose in the units stated by the code descriptor (for example, per 1 mg or per 10 mg), so billed units equal total dose divided by descriptor unit.

Code only conditions, procedures, and services documented in the medical record; documentation must support medical necessity as well as code assignment.

When the record is ambiguous, incomplete, or internally inconsistent, send a non-leading query that asks for clarification and offers clinically supported options.

An ABN documents beneficiary notice when Medicare is expected to deny a service as not medically necessary; it is not required for statutorily excluded services.

Incident-to billing requires the service be part of the physician’s plan, furnished under direct supervision, and billed under the physician’s NPI; it does not apply to hospital facility billing.

Teaching physician documentation must show the attending personally performed the service or was physically present for key portions; presence cannot be inferred.

Authentication requirements for orders and records follow payer and facility policy; verbal orders must be authenticated within the time frame set by policy.

Compliance risk areas include upcoding, unbundling, cloning documentation, and billing without medical necessity; audits compare documentation with claim data.

HIPAA minimum necessary standard limits use/disclosure of protected health information to the amount needed for the purpose.

Time-based code selection is allowed only when the CPT descriptor defines time; otherwise E/M level is based on required key components or facility criteria.

Hospital outpatient same-day surgery claims use CPT procedure codes with ICD-10-CM diagnoses; the facility reports the procedure and the professional component is billed separately by the surgeon.

Emergency department facility E/M levels 99281–99285 are selected using facility resources and interventions, not solely the physician’s history, exam, and medical decision making.

Observation services use 99218–99220 for initial, 99224–99226 for subsequent, and 99234–99236 for same-date admission/discharge; G0378 reports observation hours.

Critical care 99291 (first 30–74 minutes) and 99292 (each additional 30 minutes) require documentation of critical illness and time; facility and professional reporting rules differ.

Endoscopy facility coding reports the CPT endoscopy procedure; diagnostic and therapeutic procedures at the same session follow CPT hierarchy and NCCI bundling rather than automatic separate payment.

Hospital-based clinic visits are reported with the appropriate E/M code and facility revenue code (e.g., 0510 or 0520); the hospital and physician bill separate claims.

APC payment for outpatient services depends on the HCPCS/CPT code, status indicator, and OPPS packaging rules; packaged items are not separately paid.

Observation is an outpatient status; time begins with the order and documented observation care, and the patient is not inpatient until a formal admission order is written.

Same-day surgery implant and device charges are reported with the appropriate revenue code and HCPCS/CPT; device-intensive APC rules may apply.

Revenue codes are four-digit facility charge categories (e.g., 0360 operating room, 0450 emergency room, 0510 clinic, 0760 observation, 0636 drugs requiring detailed coding).

Under OPPS, each payable HCPCS/CPT code maps to an APC; the APC payment rate is adjusted for wage index and patient coinsurance.

Status indicators define OPPS payment: for example, T often indicates a surgical procedure subject to multiple-procedure reduction, and N indicates packaged items.

OPPS multiple-procedure reduction generally pays the second and subsequent status T procedures at 50% of the APC rate, unless an exception applies.

NCCI MUE edits set maximum units per code per date of service; exceeding an MUE without documentation causes claim denial or line adjustment.

Claim denial prevention includes verifying eligibility, obtaining prior authorization when required, and matching diagnosis, procedure, modifier, and revenue code to documentation.

Timely filing limits are payer-specific; a claim denied for timeliness may be appealable only with proof of timely submission or an exception.

Charge capture must reflect all documented services and supplies; missed charges reduce revenue, while charges not supported by documentation create compliance risk.

Deductible and coinsurance are patient liability; contractual allowance is the difference between billed charges and the payer’s allowed amount.