Lab and pathology billing runs on high volume and tight margins, so the recurring problems are panel-component unbundling, frequency limits on routine tests, and correctly distinguishing a repeat test (modifier 91) from a corrected result (modifier 76/77).
Why This Specialty Is Billing-Complex
Many lab panels (like a basic metabolic panel) bundle several individual tests into one code, and billing the individual component tests separately when a panel code applies is a frequent and easily detected error. Surgical pathology codes are also leveled by specimen complexity, and the level billed has to match the actual pathologist work documented in the report.
Common CPT, ICD-10 & HCPCS Codes
- CPT 80047 — basic metabolic panel
- CPT 80053 — comprehensive metabolic panel
- CPT 85025 — complete blood count with differential
- CPT 88305 — surgical pathology, gross and microscopic examination, level IV
- Modifier 91 — repeat clinical diagnostic laboratory test
- Modifier 90 — reference (outside) laboratory
Documentation Standards
Orders need to state the medical reason for each test or panel, since many routine labs have payer-specific frequency limits tied to a diagnosis; when a test is repeated on the same day, the record needs to show it was medically necessary (not a lab error) to support modifier 91. Pathology reports need to document the specimen complexity that justifies the CPT level billed.
Common Denial Reasons & How to Prevent Them
- Unbundling denials when individual component tests are billed instead of the applicable panel code
- Frequency-limit denials on routine labs billed more often than the payer’s policy allows
- Denials for repeat same-day tests missing modifier 91
- Denials when the surgical pathology level billed does not match the complexity documented in the report
Tools That Help
ICD-10-CM Search · Denial Code Lookup · Modifier/POS Reference · RCM Calculators · NPI Lookup