Pathology/Lab Coding Alert

Don't forget interpretation charge.

You'll need to use them for at least the rest of this year for most payers -- CPT molecular diagnostics stacking codes (83890-83914, Molecular diagnostics ...). Let's make sure you know how with our two expert tips.

Tip 1: Add Them Up

Each code in the range 83890-83914 (with one exception we'll discuss in tip 2) describes a separate technique, such as cell lysis, nucleic acid extraction, gene amplification, or nucleic acid probes.

You should bill for a single molecular assay using the stacking codes by reporting each code that describes each step the lab performs. Often, you'll report multiple units of a single code, such as 83898 (... amplification, target, each nucleic acid sequence) x 3 for an assay that involves polymerase chain reaction (PCR) for three separate nucleic acid sequences.

Tip 2: Capture Interpretation

One code represents the professional interpretation of the molecular diagnostics assay -- 83912 (... interpretation and report). How you use that code can vary depending on the payer, and whether an M.D. or PhD reports the service.

"Conventional wisdom, supported by information from the AMA, suggests the hospital or independent laboratory bills 83912 (no modifier) for payment via the clinical lab fee schedule when a technologist or PhD clinical scientist reports the test," says Dennis Padget, MBA, CPA, FHFMA, president of DLPadget Enterprises Inc. and publisher of the Pathology Service Coding Handbook, in The Villages, Fla. "But a pathologist or an independent laboratory that employs or contracts with a pathologist bills 83912-26 (Professional component) for payment from the physician fee schedule when the pathologist interprets and reports the test," he says.

Watch units: "Unlike the other codes in the 83890-83914 series, the unit of service for interpretation and report code 83912 is 'the test, according to the AMA,'" Padget says. For example, if you're looking for mutations in the Factor II and Factor V genes, that would be two tests by AMA guidance."

Caveat: CMS states in the National Correct Coding Initiative Policy Manual for Medicare that 83912 includes the synthesis of all molecular diagnostic testing performed on a single date of service. The manual makes no allowance for using a modifier such as 59 (Distinct procedural service) to allow billing multiple units.

"No exceptions are provided to this 'one unit per day' frequency limit to accommodate testing for different medical conditions, genes or gene mutations, cell lines, or any other variable," Padget says. "This is yet another instance where Medicare and the AMA differ on proper CPT reporting standards: The AMA says to report 83912 per test, but Medicare says only one unit per patient per day is allowed."