G0166

G0166 — External counterpulsation, per treatment session

HCPCSActiveBETOS P6C

G0166 is a HCPCS Level II code for external counterpulsation, per treatment session. It belongs to the Procedures and Professional Services (Temporary) section. Whether Medicare pays it depends on the coverage rule below.

Medicare coverage: Special coverage instructions apply

There are published conditions attached to this code. Check the applicable coverage policy before billing it: the code being valid is not the same as the service being covered.

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 statusA

Active code. Paid separately under the physician fee schedule.

Work RVU: 0.00
PE (non-facility): 3.04
PE (facility): 3.04
Malpractice RVU: 0.04

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 G0166 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: 2 units
outpatient: 2 units

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 G0166

Long descriptor: External counterpulsation, per treatment session
Short descriptor: Extrnl counterpulse, per tx
Added: January 1, 2000
BETOS: P6C
Pricing indicator: 11 — Physician fee schedule

Codes adjacent to G0166

HCPCS has no hierarchy — related items simply sit next to each other in the numbering. If G0166 is not quite right, the correct code is very often within a few positions of it.

G0157Services performed by a qualified physical therapist assistant in the home health or hospice setting, each 15 minutes
G0158Services performed by a qualified occupational therapist assistant in the home health or hospice setting, each 15 minutes
G0159Services performed by a qualified physical therapist, in the home health setting, in the establishment or delivery of a safe and effective physical therapy maintenance program, each 15 minutes
G0160Services performed by a qualified occupational therapist, in the home health setting, in the establishment or delivery of a safe and effective occupational therapy maintenance program, each 15 minutes
G0161Services performed by a qualified speech-language pathologist, in the home health setting, in the establishment or delivery of a safe and effective speech-language pathology maintenance program, each 15 minutes
G0162Skilled services by a registered nurse (rn) for management and evaluation of the plan of care; each 15 minutes (the patient's underlying condition or complication requires an rn to ensure that essential non-skilled care achieves its purpose in the home health or hospice setting)
G0163Skilled services of a licensed nurse (lpn or rn) for the observation and assessment of the patient's condition, each 15 minutes (the change in the patient's condition requires skilled nursing personnel to identify and evaluate the patient's need for possible modification of treatment in the home health or hospice setting)terminated
G0164Skilled services of a licensed nurse (lpn or rn), in the training and/or education of a patient or family member, in the home health or hospice setting, each 15 minutesterminated
G0168Wound closure utilizing tissue adhesive(s) only
G0173Linear accelerator based stereotactic radiosurgery, complete course of therapy in one sessionterminated
G0175Scheduled interdisciplinary team conference (minimum of three exclusive of patient care nursing staff) with patient present
G0176Activity therapy, such as music, dance, art or play therapies not for recreation, related to the care and treatment of patient's disabling mental health problems, per session (45 minutes or more)
G0177Training and educational services related to the care and treatment of patient's disabling mental health problems per session (45 minutes or more)
G0179Physician or allowed practitioner re-certification for medicare-covered home health services under a home health plan of care (patient not present), including contacts with home health agency and review of reports of patient status required by physicians and allowed practitioners to affirm the initial implementation of the plan of care
G0180Physician or allowed practitioner certification for medicare-covered home health services under a home health plan of care (patient not present), including contacts with home health agency and review of reports of patient status required by physicians and allowed practitioners to affirm the initial implementation of the plan of care
G0181Physician or allowed practitioner supervision of a patient receiving medicare-covered services provided by a participating home health agency (patient not present) requiring complex and multidisciplinary care modalities involving regular physician or allowed practitioner development and/or revision of care plans

Questions about G0166

What is HCPCS code G0166?

G0166 is a HCPCS Level II code for external counterpulsation, per treatment session. It sits in the Procedures and Professional Services (Temporary) section.

Does Medicare cover G0166?

The CMS HCPCS file marks G0166 as "Special coverage instructions apply". There are published conditions attached to this code. Check the applicable coverage policy before billing it: the code being valid is not the same as the service being covered.

How is G0166 paid under the physician fee schedule?

G0166 carries PFS status code A. Active code. Paid separately under the physician fee schedule.