Pathology/Lab Coding Alert

Question: Please explain how I should code a drug-test order for a patient on prescription phenobarbital when the physician wants to measure the therapeutic dose, plus monitor the patient for codeine and methadone use.
Oregon Subscriber

Answer: The answer depends on the payer. For non-Medicare payers, you should report the following codes

• 80184 — Phenobarbital
  

• 80361 — Opiates, 1 or more
  

• 80358 — Methadone
  

The correct code for phenobarbital is 80184, because that is a therapeutic drug assay code, and you state that the patient takes phenobarbital as a medication, and the physician orders the test to monitor the drug.

CPT 2015 provides a table that lists which drugs fall into which categories for definitive drug testing. On the table, you’ll find codeine listed in the opiate category.

Use ‘G’ codes for Medicare: CMS did not price the new drug codes for 2015, so you’ll need to turn to HCPCS Level II codes if this test order is for a Medicare patient. For a Medicare beneficiary, report the same testing with the following codes:

• 80184 — Phenobarbital
  

• G6056 — Opiates, 1 or more

• G6053 — Methadone
  

You should stick with 80184 for the phenobarbital, because that’s an existing code for a therapeutic drug assay that Medicare continues to cover this year.

Non-therapeutic is different: You asked about a case involving a therapeutic drug assay for phenobarbital, but you should note that the coding is different if the test for phenobarbital is not a therapeutic drug assay, but is instead a definitive drug test. If the patient isn’t taking phenobarbital as a medication and the physician simply orders definitive drug assays for phenobarbital, codeine, and methadone, you should code as follows for a non-Medicare patient:

• 80345 — Barbiturates
• 80361  — Opiate(s), drug and metabolites, each procedure
• 80358 — Methadone

For a Medicare beneficiary, you would code as follows:

• G6043 — Barbiturates, not elsewhere specified
  
• G6056  — Opiate(s), drug and metabolites, each procedure
• G6053  — Methadone