- Home
- Specialties
- Laboratory
Lab billing for clinical, molecular and toxicology labs
Billing for independent and physician office labs: CLIA requirements, the Clinical Laboratory Fee Schedule, toxicology codes and more.

How laboratory billing works
Every lab claim needs a valid CLIA number that matches the tests performed, plus a complete ordering provider. Medicare pays most lab tests from the Clinical Laboratory Fee Schedule (CLFS), with rates updated under PAMA.
Read more
Toxicology and molecular tests draw the most payer review, so medical necessity and the order itself must support every test billed.
Codes we bill every day
| Code | What it covers |
|---|---|
| 80305–80307 | Presumptive drug screening |
| G0480–G0483 | Definitive drug testing (Medicare), by number of drug classes |
| QW | CLIA-waived test modifier |
| 80053 / 85025 | Common panels and blood counts |
| Z-codes | Molecular test identifiers required by some MACs (MolDX) |
Code descriptions are summarized. Payer coverage and documentation rules vary by plan and state.
Denials we prevent
- Missing or mismatched CLIA certificate
- Ordering provider NPI missing or not enrolled
- Definitive drug testing without medical necessity
- Frequency limits on screening tests
- Molecular tests without required test registration
Payer rules to watch
Medicare requires the ordering or referring provider to be enrolled in Medicare. In MolDX regions, molecular tests also need a registered test identifier on the claim.
Questions about laboratory billing
Do you bill toxicology labs?
Yes, including presumptive and definitive drug testing with the documentation payers require.
Get a free laboratory billing audit
Send a few details and we will set up a short call to review your claims, denials and A/R. No cost and no commitment.
We sign a Business Associate Agreement before we handle any patient data.










