Pathology/Lab Coding Alert

Know the reason for the test.

Labs perform drug analyses using many different methods for many different reasons — how are you supposed to choose the proper codes?

Focus on the following three concepts to help you file clean claims and get the pay your lab deserves.

Tip 1: Know the CPT^® Drug Test Categories

Physicians order drug tests for a host of reasons, such as substance abuse screening, monitoring treatment regimens for pain management or addiction, or evaluating prescribed therapeutic drug levels.

CPT^® organizes drug test codes with an eye toward the lab method and reason for the test. That leads to the following three broad categories and code groupings:

1. Drug screening: CPT^® calls these “presumptive” tests, which screen for the presence or absence of drugs or drug class(es) without specific identification.

Glossary: A “drug class” is a collection of drugs that have similar chemical structure, or have the same mode of action, and/or serve the same clinical purpose.

“Presumptive test results are typically qualitative, expressed as a positive or negative finding. Clinicians often order further testing for confirmation of any positive findings,” says William Dettwyler, MT AMT, president of Codus Medicus, a laboratory coding consulting firm in Salem, Ore.

CPT^® provides three codes to describe presumptive testing based on the lab method used. You should report just one of the following codes once per day regardless of the number of drugs or drug classes involved in the screening:

• 80305 (Drug test(s), presumptive, any number of drug classes, any number of devices or procedures; capable of being read by direct optical observation only (eg, utilizing immunoassay [eg, dipsticks, cups, cards, or cartridges]), includes sample validation when performed, per date of service)
• 80306 (... read by instrument assisted direct optical observation (eg, utilizing immunoassay [eg, dipsticks, cups, cards, or cartridges]), includes sample validation when performed, per date of service)
• 80307 (… by instrument chemistry analyzers (eg, utilizing immunoassay [eg, EIA, ELISA, EMIT, FPIA, IA, KIMS, RIA]), chromatography (eg, GC, HPLC), and mass spectrometry either with or without chromatography, (eg, DART, DESI, GC-MS, GC-MS/MS, LC-MS, LC-MS/MS, LDTD, MALDI, TOF) includes sample validation when performed, per date of service).

2. Identification: To confirm positive drug screening findings and identify or quantify the specific drug(s) in the specimen, clinicians may order a “definitive” drug test. The appropriate code for the test will depend on the analyte, which CPT^® organizes alphabetically in the range 80320 (Alcohols) to 80373 (Tramadol). You’ll also have the following definitive drug test codes:

• 80374 (Stereoisomer (enantiomer) analysis, single drug class)
• 80375 (Drug(s) or substance(s), definitive, qualitative or quantitative, not otherwise specified; 1-3)
• 80376 (… 4-6)
• 80377 (… 7 or more).

3. Therapeutic: CPT^® also provides codes for therapeutic drug test listed alphabetically in the range 80413 (Acetaminophen) to 80203 (Zonisamide), plus code 80299 (Quantitation of therapeutic drug, not elsewhere specified). Some of the codes are out of numerical sequence, indicated by the # symbol.

“You should use a therapeutic drug assay code only when the clinician orders a test to monitor patient response to a known, prescribed medication,” Dettwyler says. That may be to evaluate a change in the patient’s clinical state or treatment response, or to consider blood concentration related to dosage, drug interactions, or possible toxicity.

Caution: Don’t use a therapeutic drug assay code for a non-prescribed medication. If a clinician orders a test based on the suspicion that a patient is abusing a drug without a prescription, you need to turn to a definitive drug test code, even if the drug is listed in the Therapeutic Drug Assay section.

Tip 2: Recognize HCPCS Level II Alternatives

Medicare does not accept the CPT^® definitive drug test codes. Instead, you’ll need to turn to the following codes for Medicare beneficiaries:

• G0480 (Drug test(s), definitive, utilizing (1) drug identification methods able to identify individual drugs and distinguish between structural isomers (but not necessarily stereoisomers), including, but not limited to GC/MS (any type, single or tandem) and LC/MS (any type, single or tandem and excluding immunoassays (e.g., IA, EIA, ELISA, EMIT, FPIA) and enzymatic methods (e.g., alcohol dehydrogenase)), (2) stable isotope or other universally recognized internal standards in all samples (e.g., to control for matrix effects, interferences and variations in signal strength), and (3) method or drug-specific calibration and matrix-matched quality control material (e.g., to control for instrument variations and mass spectral drift); qualitative or quantitative, all sources, includes specimen validity testing, per day; 1-7 drug class(es), including metabolite(s) if performed)
• G0481 (... 8-14 drug class(es), including metabolite(s) if performed)
• G0482 (... 15-21 drug class(es), including metabolite(s) if performed)
• G0483 (... 22 or more drug class(es), including metabolite(s) if performed)
• G0659 (Drug test(s), definitive, utilizing drug identification methods able to identify individual drugs and distinguish between structural isomers (but not necessarily stereoisomers), including but not limited to GC/MS (any type, single or tandem) and LC/MS (any type, single or tandem), excluding immunoassays (e.g., IA, EIA, ELISA, EMIT, FPIA) and enzymatic methods (e.g., alcohol dehydrogenase), performed without method or drug-specific calibration, without matrix-matched quality control material, or without use of stable isotope or other universally recognized internal standard(s) for each drug, drug metabolite or drug class per specimen; qualitative or quantitative, all sources, includes specimen validity testing, per day, any number of drug classes).

Medicaid: Many state Medicaid agencies require H0003 (Alcohol and/or drug screening; laboratory analysis of specimens for presence of alcohol and/or drugs) to identify mental health services related to alcohol and drug-abuse treatment.

Tip 3: Get the Dx Coding Right

Clinicians may order a screening drug test using a specific code that describes the clinical situation, such as known drug dependency (F19.- Other psychoactive substance related disorders) or symptoms such as altered consciousness (R40.- Somnolence, stupor and coma).

When a screening test returns abnormal findings, the clinician may order definitive drug testing using a code from the family R78.- (Findings of drugs and other substances, not normally found in blood).

Therapeutic: To support medical necessity for therapeutic drug testing, you should choose one of the following ICD-10-CM codes:

• Z79.0- (Long term (current) use of anticoagulants and antithrombotics/antiplatelets)
• Z79.1 (… non-steroidal anti-inflammatories (NSAID))
• Z79.2 (… antibiotics)
• Z79.3 (… hormonal contraceptives)
• Z79.4 (… Insulin)
• Z79.5- (… steroids)
• Z79.60 (… immunomodulators and immunosuppressants)
• Z79.61 (… immunomodulator)
• Z79.62- (… immunosuppressant)
• Z79.63- (… chemotherapeutic agent)
• Z79.64 (… myelosuppressive agent)
• Z79.69 (… other immunomodulators and immunosuppressants)
• Z79.81- (… agents affecting estrogen receptors and estrogen levels)
• Z79.82 (… aspirin)
• Z79.83 (… bisphosphonates)
• Z79.84 (… hypoglycemic drugs)
• Z79.85 (… injectable non-insulin antidiabetic drugs)
• Z79.89- (Other long term (current) drug therapy)

“When patients require laboratory testing to ensure drug efficacy and safety, the claim reporting is better serviced with the addition of a specific Z79.- code that identifies the therapy the patient is receiving,” says Carol Pohlig, BSN, RN, CPC, ACS, senior coding and education specialist for the University of Pennsylvania Department of Medicine, Hospital of the University of Pennsylvania. “Adding a diagnosis from this expanded category provides a better electronic explanation of these tests or treatments,” Pohlig adds.

Notice: You should use one of these codes only when the documentation shows that the patient is currently taking the medication, and that the use is “long term.”

Glossary: ICD-10-CM does not specify a time frame for “long term” use. However, the guidelines state that you should “assign a code from Z79 if the patient is receiving a medication for an extended period as a prophylactic measure (such as for the prevention of deep vein thrombosis) or as treatment of a chronic condition (such as arthritis) or a disease requiring a lengthy course of treatment (such as cancer),” per guideline I.C.21.c.3.

Alternatively, the guideline also says you should not assign a code from Z79.- “for medication being administered for a brief period of time to treat an acute illness or injury (such as a course of antibiotics to treat acute bronchitis).”

Bottom line: Assign a Z79.- code if the patient is taking a drug over an extended period of time (“long-term”) for a chronic condition, and the patient is taking the medication at the time of the encounter (“current”).