G0399 — Home sleep test (hst) with type iii portable monitor, unattended; minimum of 4 channels: 2 respiratory movement/airflow, 1 ecg/heart rate and 1 oxygen saturation
G0399 is a HCPCS Level II code for home sleep test (hst) with type iii portable monitor, unattended; minimum of 4 channels: 2 respiratory movement/airflow, 1 ecg/heart rate and 1 oxygen saturation. 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 statusC
Contractor-priced. Your MAC establishes the RVUs and the payment amount case by case, usually after reviewing documentation. There is no national amount to compute.
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 G0399 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 G0399
- Long descriptor
- Home sleep test (hst) with type iii portable monitor, unattended; minimum of 4 channels: 2 respiratory movement/airflow, 1 ecg/heart rate and 1 oxygen saturation
- Short descriptor
- Home sleep test/type 3 porta
- Added
- March 13, 2008
- BETOS
- T2D
- Pricing indicator
- 13 — Physician fee schedule
The official wording. This is what the code means.
CMS's 28-character form, which is what shows up on a remittance advice.
When CMS introduced the code.
Berenson-Eggers Type of Service — CMS's own analytic grouping.
Price established by carriers — not otherwise classified, individual determination, or carrier discretion.
Codes adjacent to G0399
HCPCS has no hierarchy — related items simply sit next to each other in the numbering. If G0399 is not quite right, the correct code is very often within a few positions of it.
- G0382Level 3 hospital emergency department visit provided in a type b emergency department; (the ed must meet at least one of the following requirements: (1) it is licensed by the state in which it is located under applicable state law as an emergency room or emergency department; (2) it is held out to the public (by name, posted signs, advertising, or other means) as a place that provides care for emergency medical conditions on an urgent basis without requiring a previously scheduled appointment; or (3) during the calendar year immediately preceding the calendar year in which a determination under 42 cfr 489.24 is being made, based on a representative sample of patient visits that occurred during that calendar year, it provides at least one-third of all of its outpatient visits for the treatment of emergency medical conditions on an urgent basis without requiring a previously scheduled appointment)
- G0383Level 4 hospital emergency department visit provided in a type b emergency department; (the ed must meet at least one of the following requirements: (1) it is licensed by the state in which it is located under applicable state law as an emergency room or emergency department; (2) it is held out to the public (by name, posted signs, advertising, or other means) as a place that provides care for emergency medical conditions on an urgent basis without requiring a previously scheduled appointment; or (3) during the calendar year immediately preceding the calendar year in which a determination under 42 cfr 489.24 is being made, based on a representative sample of patient visits that occurred during that calendar year, it provides at least one-third of all of its outpatient visits for the treatment of emergency medical conditions on an urgent basis without requiring a previously scheduled appointment)
- G0384Level 5 hospital emergency department visit provided in a type b emergency department; (the ed must meet at least one of the following requirements: (1) it is licensed by the state in which it is located under applicable state law as an emergency room or emergency department; (2) it is held out to the public (by name, posted signs, advertising, or other means) as a place that provides care for emergency medical conditions on an urgent basis without requiring a previously scheduled appointment; or (3) during the calendar year immediately preceding the calendar year in which a determination under 42 cfr 489.24 is being made, based on a representative sample of patient visits that occurred during that calendar year, it provides at least one-third of all of its outpatient visits for the treatment of emergency medical conditions on an urgent basis without requiring a previously scheduled appointment)
- G0389Ultrasound b-scan and/or real time with image documentation; for abdominal aortic aneurysm (aaa) screeningterminated
- G0390Trauma response team associated with hospital critical care service
- G0396Alcohol and/or substance (other than tobacco) misuse structured assessment (e.g., audit, dast), and brief intervention 15 to 30 minutes
- G0397Alcohol and/or substance (other than tobacco) misuse structured assessment (e.g., audit, dast), and intervention, greater than 30 minutes
- G0398Home sleep study test (hst) with type ii portable monitor, unattended; minimum of 7 channels: eeg, eog, emg, ecg/heart rate, airflow, respiratory effort and oxygen saturation
- G0400Home sleep test (hst) with type iv portable monitor, unattended; minimum of 3 channels
- G0402Initial preventive physical examination; face-to-face visit, services limited to new beneficiary during the first 12 months of medicare enrollment
- G0403Electrocardiogram, routine ecg with 12 leads; performed as a screening for the initial preventive physical examination with interpretation and report
- G0404Electrocardiogram, routine ecg with 12 leads; tracing only, without interpretation and report, performed as a screening for the initial preventive physical examination
- G0405Electrocardiogram, routine ecg with 12 leads; interpretation and report only, performed as a screening for the initial preventive physical examination
- G0406Follow-up inpatient consultation, limited, physicians typically spend 15 minutes communicating with the patient via telehealth
- G0407Follow-up inpatient consultation, intermediate, physicians typically spend 25 minutes communicating with the patient via telehealth
- G0408Follow-up inpatient consultation, complex, physicians typically spend 35 minutes communicating with the patient via telehealth
Questions about G0399
What is HCPCS code G0399?
G0399 is a HCPCS Level II code for home sleep test (hst) with type iii portable monitor, unattended; minimum of 4 channels: 2 respiratory movement/airflow, 1 ecg/heart rate and 1 oxygen saturation. It sits in the Procedures and Professional Services (Temporary) section.
Does Medicare cover G0399?
The CMS HCPCS file marks G0399 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 G0399 paid under the physician fee schedule?
G0399 carries PFS status code C. Contractor-priced. Your MAC establishes the RVUs and the payment amount case by case, usually after reviewing documentation. There is no national amount to compute.