Last reviewed: October 2026
There’s no single ICD-10 code for a drug screen. The code depends on why the test was ordered: employment or legal testing, monitoring a patient on long-term opioids, substance use disorder treatment, or a suspected overdose. Picking the right reason decides whether the test is covered at all. This guide lists the ICD-10 codes used for drug screening and when each applies.
ICD-10 Codes for Drug Screening by Reason
| Reason for the test | ICD-10 code(s) | Notes |
|---|---|---|
| Employment, court-ordered or other non-medical drug test | Z02.83 Encounter for blood-alcohol and blood-drug test | First-listed code only. Insurance, including Medicare, generally doesn’t cover non-medical testing; bill the employer or patient |
| Monitoring a patient on long-term opioid therapy | Z79.891 Long-term (current) use of opiate analgesic, with Z51.81 Encounter for therapeutic drug level monitoring | The most common code pair for pain management practices |
| Monitoring other long-term drug therapy | Z79.899 Other long-term (current) drug therapy, with Z51.81 | For example, benzodiazepines or stimulants prescribed long-term |
| Substance use disorder treatment | F-codes for the disorder, such as F11.20 (opioid dependence, uncomplicated), F11.21 (opioid dependence, in remission), F12.20 (cannabis dependence) or F14.20 (cocaine dependence) | Code the specific substance and status from the provider’s documentation |
| Counseling and surveillance of a patient with drug abuse | Z71.51 Drug abuse counseling and surveillance of drug abuser | Add the F-code for the substance use disorder |
| Drugs found in a test result | R78.0–R78.6 Findings of drugs and alcohol in blood (for example, R78.1 opiate, R78.2 cocaine); R82.5 Elevated urine level of drugs, medicaments and biological substances | Use when a result is reported and no diagnosis explains it |
| Suspected poisoning or overdose | T-codes for the poisoning (for example, T40.- for opioids and other narcotics), plus symptom codes | Follow ICD-10-CM poisoning guidelines |
Which Code Comes First?
- Non-medical testing: Z02.83 is first-listed only. If the result is positive, add the R78 code for the finding.
- Medication monitoring: list the long-term drug therapy code (Z79.891 or Z79.899) with Z51.81, plus the condition being treated, such as chronic pain.
- Substance use disorder: the F-code describes the condition; Z71.51 can be added when the visit includes counseling and surveillance.
The diagnosis has to come from the ordering provider’s documentation. A lab can’t choose a code that makes the test covered if the order doesn’t support it.
Medicare Rules for Drug Testing
Medicare contractors cover drug testing through local coverage determinations, titled “Controlled Substance Monitoring and Drugs of Abuse Testing” in several jurisdictions. In general:
- Testing has to be ordered for the individual patient, based on their history and risk. Blanket orders for every patient aren’t considered medically necessary.
- Presumptive (screening) tests usually come first. Definitive tests should be limited to the drugs the provider needs to confirm or identify.
- Coverage and frequency limits depend on the patient’s risk level, so the record should show why each test was needed.
- Employment, court-ordered and other non-medical testing isn’t covered.
Drug Testing CPT and HCPCS Codes
The diagnosis has to match the test billed:
- 80305–80307: presumptive drug tests, by method.
- G0480–G0483: definitive drug tests for Medicare, by the number of drug classes tested.
- 80320–80377: definitive drug tests by drug, used by many commercial payers.
Drug testing is one of the most audited areas in lab billing. Our laboratory billing services check orders, diagnosis codes and payer frequency limits before toxicology claims go out. For addiction treatment programs, see our behavioral health billing services.
FAQs
What is the ICD-10 code for a drug screen?
It depends on the reason. Use Z02.83 for employment or other non-medical testing, Z79.891 with Z51.81 for monitoring long-term opioid therapy, and the F-code for a substance use disorder.
What is Z02.83 used for?
Z02.83 is “Encounter for blood-alcohol and blood-drug test.” It’s used for non-medical testing, such as for employment or court orders, and only as the first-listed code.
Does insurance cover drug screening for employment?
Generally no. Medicare and most insurers don’t cover non-medical drug testing, so the employer or patient usually pays.
What ICD-10 code is used for a positive drug screen?
Use the R78 code for the drug found in blood, such as R78.1 for an opiate or R78.2 for cocaine, or R82.5 for an elevated urine level, unless a diagnosis already explains the result.
What ICD-10 code supports drug testing for patients on opioids?
Z79.891 (long-term use of opiate analgesic) with Z51.81 (therapeutic drug level monitoring), plus the condition being treated.