Pathology/Lab Coding Alert

Stick with 80100-80104 for ordered screening.

Your lab may have high-complexity methods for quantifying drugs of abuse or therapeutic drugs, but that doesn’t mean you can pull out the “big guns,” coding wise, for every test.

In other words, you shouldn’t use codes for therapeutic drug assay (80150-80299) or chemistry (82000-84999) if what the doctor ordered is a drug screen.

Read on to let our experts teach you how to choose the right code(s) for all your drug screen tests.

Step 1: See What’s Requested

When a physician orders a drug screen, whether for drugs of abuse or therapeutic drugs, you must use “drug testing” codes to report the service.

“Some labs and billing companies are under the impression that they can report a drug screen using therapeutic drug assay or chemistry codes for each drug tested if they use complex lab methods capable of reporting quantitative results, but that’s just not the case,” says William Dettwyler, MTAMT, president of Codus Medicus, a laboratory coding consulting firm in Salem, Ore.

Take orders: The lab should test and bill based on what the doctor requests. If the physician orders a drug screen, the service involves assaying for ordered drugs or drug classes, and reporting the presence or absence (positive or negative results) for each drug or drug class.

Step 2: Know Your Payer

Now that you know you’re looking for drug testing codes, not quantitative therapeutic drug assays or chemistry test codes, where do you turn?

CPT^® provides a section for “Drug Testing” that includes the following codes:

• 80100 — Drug screen, qualitative; multiple drug classes chromatographic method, each procedure
• 80101 — Drug screen, qualitative; single drug class method (e.g., immunoassay, enzyme assay), each drug class
• # 80104 — Drug screen, qualitative; multiple drug classes other than chromatographic method, each procedure
• 80102 — Drug confirmation, each procedure
• 80103 — Tissue preparation for drug analysis.

That’s not all: Here’s where knowing the payer comes in. Medicare doesn’t cover codes 80100, 80101, or 80104 for drug screens. Instead, you’ll need to choose a HCPCS Level II code if Medicare is the payer. Read “G0431, G0434 Define Your Options” on page 94 of this issue to learn how to bill Medicare for drug testing. 

Step 3: Identify the Lab Method

You’ll notice that the three drug screen codes (80100, 80101, and 80104) differ based on the lab method, such as chromatography or immunoassay, as well as whether the test uses single or multiple procedures to identify multiple drug classes.

Do this: Use 80100 for drug screens using complex chromatographic instruments. Report 80101 for drug screens using complex chemistry analyzers that involve distinct analyses per drug class. Finally, reserve 80104 for multiplexed methods that identify multiple drug classes in a single procedure, such as drug test kits using cups or test strips.

Caution: Some drug screen kits have descriptions that might confuse coders by describing immunoassay methods in the test kit insert. “But as long as you’re using a test kit that identifies multiple drug classes in a single procedure, you must choose 80104 instead of 80101,” Dettwyler cautions.

Watch units: Don’t assume that you should code just one unit of 80100, 80101, or 80104 for each drug screen. The units of service are different for the three methods, as follows:

• 80100: You should report 80100 per procedure. The CPT^® definition of “each procedure” for chromatography is a single stationary and mobile phase, regardless of the number of analytes (drugs or drug classes) that you examine. For instance, testing for two drugs with a single stationary/mobile phase earns 80100, while testing for two drugs with a stationary phase and two mobile phases earns 80100 x 2.
• 80101: If your lab screens for drugs using instrumentation that involves “single drug class method,” such as a laboratory analyzer using immunoassay technique, you can report 80101 once per drug class, such as “alcohols” or “opiates.”
• 80104: If your lab uses one of the test kits or point-of-care analyzers that screen for multiple drugs or drug classes in a single procedure, you should report only one unit of 80104. “You should not code per drug class as you do for 80101, because the unit of service for 80104 is ‘each procedure,’” explains Robin Miller Zweifel, MT (ASCP), a laboratory coding and billing compliance consultant in Niota, Tenn.

Step 4: Capture Subsequent Tests

Typically, physicians request confirmation of any drugs that show positive results in the screening. That’s when you should use an additional code — 80102 — for each procedure. 

For example: Depending on the drugs and the lab method, running a confirmation test for two drugs might be a single unit of 80102 or 80102 x 2. For instance, a liquid chromatography-mass spectrometry (LC-MS) confirmation test for two drugs with a single stationary and mobile phase would be 80102. But if the confirmation test for the two drugs using the same instrument requires a stationary phase and two mobile phases, you should charge two units of 80102.

Key: Report 80102 per procedure. The results may be qualitative or quantitative. As CPT^® states in the drug testing introduction, “confirmed drugs may also be quantitated.”

Look for quantification: The physician may specifically order quantification for certain substances to evaluate suspected toxicity or compliance concerns or therapeutic range, among other reasons. For these procedures you should select the appropriate code(s) for the specific substances from the therapeutic drug assay (80150-80299) or chemistry (82000-84999) sections. For quantification of an unlisted therapeutic drug, you should report 80299 (Quantitation of drug, not elsewhere specified).