Pathology/Lab Coding Alert

Grasp ‘definitive’ terminology, too.

If your lab performs toxicology testing, you need to understand the lingo and the testing hierarchy that impacts lab’s work, and your code choices.

Missing the mark on billing drug tests could cost your lab money — or lead to charges of fraud. Read on to understand some basic concepts for toxicology.

Clarify Drugs-Of-Abuse Coding

When testing patients for drugs of abuse, labs frequently perform a “screening” test first, followed by a “confirmatory” test based on a positive screening result. The screening tests analyze the specimen to see if the patient possibly did or did not use drug(s) in specific class (es), but the tests don’t specifically identify or measure a single drug.

The lab typically follows up a positive screen with a confirmatory test, which identifies and measures any specific drug(s) present in the specimen. Most payers won’t cover these tests without a medically-necessary reason, such as a positive screening test, or symptoms that indicate suspicion of drug overdose.

Since the CPT^® drug-code overhaul in 2015, coding for screening and confirmatory testing have roughly corresponded to the following sections:

• Presumptive drug class screening: The tests in the range 80300-80304 (Drug screen …) evaluate the patient specimen for the presence of drug(s) in specific class (es). CPT^® divides these codes primarily into two drug lists based on the test complexity: List A and List B. Presumptive tests don’t identify a specific drug, and can’t distinguish between structural isomers (such as morphine and hydromorphone). Clinicians may order additional testing (see the next subsection) based on presumptive test results.
• Definitive drug testing: Each code in the range 80320-80377 represents a different drug class or drug, and includes all drugs and metabolites in the listed class (except for rare cases that involve a specific metabolite code). The definitive tests are more specific than presumptive tests, and can identify individual drugs and distinguish between structural isomers (but not necessarily stereoisomers). Clinicians may order definitive testing as the first test, or as a confirmatory test following a positive screening drug test.

Medicare alert: Although these same concepts of presumptive and confirmatory testing apply to all patients, payers such as Medicare require different codes. You can read about those rules in “Expect 2-Tier Drugs-of-Abuse Reporting for Medicare” on page 91.