Pathology/Lab Coding Alert

-Unit of service- changes reimbursement for this CF assay.

Although the AMA only intended for CPT 2009 molecular diagnostics code changes to "clarify the original intent of the codes," you just might need to change the way you report some assays.

Look back to last month's article, "Rev Up Your Molecular Diagnostics Coding With These Tips," for an overview of the CPT update. Then get ready to possibly change the way you report some steps in a molecular diagnostics assay.

By clearly defining the units of service for steps in a molecular diagnostics assay, CPT 2009 may alter the way you code. Look at the following case in point:

"Adding -each enzyme treatment- to 83892 [Molecular diagnostics, enzymatic digestion, each enzyme treatment] changes how you should report that code for some of our Third Wave Technologies tests," says Stephen Day, PhD, director of medical affairs for Third Wave Technologies/ Hologic in Madison, Wis.

For example: Look at how you-ll report the InPlex- CF molecular testing for 46 cystic fibrosis mutations:

-83891 -- Molecular diagnostics; isolation or extraction of highly purified nucleic acid, each nucleic acid type (i.e. DNA or RNA)

Because the test involves only one DNA extraction, coding for this step does not change.

For the 19-plex polymerase chain reaction (PCR) that amplifies the genetic material, use two codes as follows:

-83900 -- Molecular diagnostics; amplification, target, multiplex, first 2 nucleic acid sequences

-+83901 x 17 -- ...amplification, target, multiplex, each additional nucleic acid sequence beyond 2 (List separately in addition to code for primary procedure)

Next, the lab adds buffer and Cleavase- enzyme, then distributes it to individual reaction chambers, reconstituting the oligonucleotides in 46 individual reaction chambers and sealing the chambers. This, in effect, results in 46 individual reactions with two cleavages each.

"The test involves two cleavages per mutation (46 mutations), and in the past, that meant coding 83892 x 92," Day says. "But because you only add the enzyme once, you should now report only one unit of 83892 under the new definition."

-83892 -- Molecular diagnostics; enzymatic digestion; each enzyme treatment

That means getting paid $5.60 for the enzyme digestion step instead of $515.20. You need to update your coding so you don't get stuck repaying almost $510 if you bill it incorrectly.

Your lab may or may not see payment changes from the CPT 2009 molecular diagnostics revisions, depending on what tests you-re doing.

"I think the CPT changes are appropriately done, and may bring potential reimbursement payments for some molecular tests into line with what their true cost to perform should be," Day says.