G0399 HCPCS code: 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 the 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. In 2024 Medicare paid an average of $50.30 per service for G0399 across 73,440 services. Its Medicare coverage code is C (Carrier judgment): Coverage is decided by the Medicare contractor (MAC) case by case. The NCCI unit limit is 1 per day on outpatient hospital claims. Medicare volume fell 14% from 2022 to 2024 (85,571 to 73,440 services). In 2024, about 2,553 clinicians billed Medicare for G0399 for 64,539 beneficiaries; California, Florida, Pennsylvania accounted for 26% of services.

Code details

Who bills G0399 (2024)

Counts only. Supplier and clinician names, contact lists and state-by-state detail are in Caduvo.

Medicare utilization for G0399, 2022–2024

States with the most G0399 services (2024)

NCCI unit limits (MUE)

Medicare policy articles for this code

• A53019: Polysomnography and Sleep Studies – Medical Policy Article (Wellpoint Federal (MAC - Part A, MAC - Part B))
• A56903: Billing and Coding: Polysomnography and Other Sleep Studies (WPS Insurance Corporation (MAC - Part A, MAC - Part B))
• A56923: Billing and Coding: Outpatient Sleep Studies (Novitas Solutions, Inc. (MAC - Part A, MAC - Part B))
• A56995: Billing and Coding: Polysomnography (Palmetto GBA (MAC - Part A, MAC - Part B))
• A57049: Billing and Coding: Polysomnography and Other Sleep Studies (CGS Administrators, LLC (MAC - Part A, MAC - Part B))
• A57496: Billing and Coding: Polysomnography and Sleep Testing (First Coast Service Options, Inc. (MAC - Part A, MAC - Part B))
• A57697: Billing and Coding: Polysomnography and Other Sleep Studies (Noridian Healthcare Solutions, LLC (MAC - Part A, MAC - Part B))
• A58559: Billing and Coding: Independent Diagnostic Testing Facilities (IDTF) (Palmetto GBA (MAC - Part B))

Covered diagnoses (87 ICD-10-CM codes)

The diagnoses most often listed as covered in the policy articles above:

Showing 10 of 87. The full list, non-covered diagnoses and CSV export are in Caduvo.

What changed for G0399

• 2008-03-13: G0399 added to HCPCS Level II
• Next scheduled CMS quarterly update (HCPCS and DMEPOS fee schedule): 2027-01-01

Frequently asked questions

What is HCPCS code G0399?

G0399 is the 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. Short descriptor: "Home sleep test/type 3 porta".

How much does Medicare pay for G0399?

In 2024, the average Medicare payment was $50.30 per service (average allowed $67.68).

Does Medicare cover G0399?

Coverage code C — Carrier judgment. Coverage is decided by the Medicare contractor (MAC) case by case.

Which diagnoses support coverage for G0399?

Medicare policy articles that cite G0399 list 87 covered ICD-10-CM diagnosis codes across 8 articles. The most cited include G47.10 (Hypersomnia, unspecified), G47.11 (Idiopathic hypersomnia with long sleep time), G47.12 (Idiopathic hypersomnia without long sleep time). A listed diagnosis is necessary but not sufficient; the policy's other criteria still apply.

How many units of G0399 can be billed per day?

1 on outpatient hospital claims; 1 on practitioner claims (NCCI medically unlikely edits).

Related G03 codes

• G0300 — Direct skilled nursing services of a licensed practical nurse (lpn) in the home health or hospice setting, each 15 minutes
• G0302 — Pre-operative pulmonary surgery services for preparation for lvrs, complete course of services, to include a minimum of 16 days of services
• G0303 — Pre-operative pulmonary surgery services for preparation for lvrs, 10 to 15 days of services
• G0304 — Pre-operative pulmonary surgery services for preparation for lvrs, 1 to 9 days of services
• G0305 — Post-discharge pulmonary surgery services after lvrs, minimum of 6 days of services
• G0306 — Complete cbc, automated (hgb, hct, rbc, wbc, without platelet count) and automated wbc differential count
• G0307 — Complete (cbc), automated (hgb, hct, rbc, wbc; without platelet count)
• G0308 — Creation of subcutaneous pocket with insertion of 180 day implantable interstitial glucose sensor, including system activation and patient training
• G0309 — Removal of implantable interstitial glucose sensor with creation of subcutaneous pocket at different anatomic site and insertion of new 180 day implantable sensor, including system activation
• G0310 — Immunization counseling by a physician or other qualified health care professional when the vaccine(s) is not administered on the same date of service, 5 to 15 mins time (this code is used for medicaid billing purposes)
• G0311 — Immunization counseling by a physician or other qualified health care professional when the vaccine(s) is not administered on the same date of service, 16-30 mins time (this code is used for medicaid billing purposes)
• G0312 — Immunization counseling by a physician or other qualified health care professional when the vaccine(s) is not administered on the same date of service for ages under 21, 5 to 15 mins time (this code is used for medicaid billing purposes)

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Next steps

• Run a reimbursement report for a device billed under G0399
• Watch G0399 for fee, coverage and descriptor changes
• Build a full Medicare revenue model for G0399

Sources: CMS HCPCS Level II release October 2026; CMS DMEPOS fee schedule; CMS NCCI MUE tables; CMS Medicare utilization (physician and DME supplier files); CMS Medicare Coverage Database articles. Fees are Medicare allowables, not commercial rates. Not billing or legal advice.

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