MCMCB Pro
G0659

G0659Drug 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

HCPCSActiveBETOS T1H

G0659 is a HCPCS Level II code for 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. It belongs to the Procedures and Professional Services (Temporary) section. Whether Medicare pays it depends on the coverage rule below.

Medicare coverage: Carrier judgment

Coverage is decided by your Medicare contractor, not by national policy. Whether this is paid depends on the LCD for your jurisdiction and on what the documentation supports.

From the coverage field of the CMS Alpha-Numeric HCPCS File, release 2026Q3-Jul. This states Medicare’s position on the code, not on your particular claim.

Physician fee schedule statusX

Statutory exclusion. The item or service is not within the statutory definition of 'physician services', so the fee schedule never pays it.

Global period: XXX

Want the dollar amount for your locality? The fee calculator applies your GPCI and the current conversion factor.

Medically Unlikely Edits — units per day

The most units of G0659 Medicare will pay on one date of service. Bill more on a single line and it is denied. The limit is not the same in every setting, so the row that matters is the one matching the claim you are building.

practitioner
1 unit
MAI 2 — Date of Service Edit: Policy · Code Descriptor / CPT Instruction
outpatient
1 unit
MAI 2 — Date of Service Edit: Policy · Code Descriptor / CPT Instruction

The adjudication indicator decides whether exceeding the limit is worth appealing at all: MAI 1 is a line edit you can support with documentation, MAI 3 is a date-of-service edit that is also appealable, and MAI 2 is absolute — no documentation overrides it. CMS MUE 2026Q3.

The CMS record for G0659

Long descriptor
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

The official wording. This is what the code means.

Short descriptor
Drug test def simple all cl

CMS's 28-character form, which is what shows up on a remittance advice.

Added
January 1, 2017

When CMS introduced the code.

BETOS
T1H

Berenson-Eggers Type of Service — CMS's own analytic grouping.

Pricing indicator
21 — Clinical lab fee schedule

Price subject to the national limitation amount.

Codes adjacent to G0659

HCPCS has no hierarchy — related items simply sit next to each other in the numbering. If G0659 is not quite right, the correct code is very often within a few positions of it.

  • G0567Infectious agent detection by nucleic acid (dna or rna); hepatitis c, screening, amplified probe technique
  • G0568Initial psychiatric collaborative care management, in the first calendar month of behavioral health care manager activities, in consultation with a psychiatric consultant, and directed by the treating physician or other qualified health care professional, with the following required elements: outreach to and engagement in treatment of a patient directed by the treating physician or other qualified health care professional, initial assessment of the patient, including administration of validated rating scales, with the development of an individualized treatment plan, review by the psychiatric consultant with modifications of the plan if recommended, entering patient in a registry and tracking patient follow-up and progress using the registry, with appropriate documentation, and participation in weekly caseload consultation with the psychiatric consultant, and provision of brief interventions using evidence-based techniques such as behavioral activation, motivational interviewing, and other focused treatment strategies (list separately in addition to the advanced primary care management code)
  • G0569Subsequent psychiatric collaborative care management, in a subsequent month of behavioral health care manager activities, in consultation with a psychiatric consultant, and directed by the treating physician or other qualified health care professional, with the following required elements: tracking patient follow-up and progress using the registry, with appropriate documentation, participation in weekly caseload consultation with the psychiatric consultant, ongoing collaboration with and coordination of the patient's mental health care with the treating physician or other qualified health care professional and any other treating mental health providers, additional review of progress and recommendations for changes in treatment, as indicated, including medications, based on recommendations provided by the psychiatric consultant, provision of brief interventions using evidence-based techniques such as behavioral activation, motivational interviewing, and other focused treatment strategies, monitoring of patient outcomes using validated rating scales, and relapse prevention planning with patients as they achieve remission of symptoms and/or other treatment goals and are prepared for discharge from active treatment (list separately in addition to advanced primary care management code)
  • G0570Care management services for behavioral health conditions, directed by a physician or other qualified health care professional, per calendar month, with the following required elements: initial assessment or follow-up monitoring, including the use of applicable validated rating scales, behavioral health care planning in relation to behavioral/psychiatric health problems, including revision for patients who are not progressing or whose status changes, facilitating and coordinating treatment such as psychotherapy, pharmacotherapy, counseling and/or psychiatric consultation, and continuity of care with a designated member of the care team (list separately in addition to advanced primary care management code)
  • G0571Intraoperative nerve(s) cryoablation for post-surgical pain relief (list separately in addition to code for primary service)
  • G0574Management of new patient with dementia residing in an eligible residential care community, for use only in a medicare-approved cmmi model (services must be furnished within a patient's eligible residential care community, including assisted living facilities, board and care homes, or other qualifying residential settings where dementia care services are provided)
  • G0575Management of established patient with dementia residing in an eligible residential care community, for use only in a medicare-approved cmmi model (services must be furnished within a patient's eligible residential care community, including assisted living facilities, board and care homes, or other qualifying residential settings where dementia care services are provided)
  • G0577Vascular embolization or occlusion procedure with use of a pressure-generating catheter (e.g., one-way valve, intermittently occluding), inclusive of all radiological supervision and interpretation, intraprocedural roadmapping, and imaging guidance necessary to complete the intervention; for tumors, organ ischemia, or infarction performed in the non-facility setting
  • G0660Team remote e/m new pt 10mins
  • G0661Team remote e/m new pt 20mins
  • G0662Team remote e/m new pt 30 mins
  • G0663Team remote e/m new pt 45mins
  • G0664Team remote e/m new pt 60mins
  • G0665Team remote e/m est. pt 10mins
  • G0666Team remote e/m est. pt 15mins
  • G0667Team remote e/m est. pt 25mins

Questions about G0659

What is HCPCS code G0659?

G0659 is a HCPCS Level II code for 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. It sits in the Procedures and Professional Services (Temporary) section.

Does Medicare cover G0659?

The CMS HCPCS file marks G0659 as "Carrier judgment". Coverage is decided by your Medicare contractor, not by national policy. Whether this is paid depends on the LCD for your jurisdiction and on what the documentation supports.

How is G0659 paid under the physician fee schedule?

G0659 carries PFS status code X. Statutory exclusion. The item or service is not within the statutory definition of 'physician services', so the fee schedule never pays it.

HCPCS Level II2026Q3-Jul· effective July 1, 2026