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HCPCS G0399 · Level II · G code

G0399: Home sleep test (hst) with type iii portable monitor, unattended, HCPCS Level II G code

Compiled from CMS files by the QuickIntell RCM Editorial Team · Data effective · Method: reference methodology · Report a data correction

Data currency: HCPCS Level II file: October 2026 (effective October 1, 2026); PFS relative value file: RVU26D, released August 26, 2026 (effective October 1, 2026); NCCI MUE tables: 2026 Q4 (effective October 1, 2026); NCCI PTP edits: v323r0 (2026 Q4) (effective October 1, 2026); OPPS Addendum B: October 2026 (effective October 1, 2026); Medicare Coverage Database LCD export: MCD release October 8, 2026 (effective October 4, 2026). Next CMS release: January 1, 2027 (quarterly update) for the HCPCS Level II file and NCCI MUE tables and NCCI PTP edits and OPPS Addendum B; RVU27A with the CY2027 PFS final rule, effective January 1, 2027 for the PFS relative value file; weekly, every Thursday for the Medicare Coverage Database LCD export.

Key facts for G0399

Medicare payment
$220.60
OPPS rate, SI S
Coverage code
C
carrier judgment, so the Medicare contractor decides coverage
Facility outpatient MUE
1
MAI 2
OPPS status
SI S
Procedure or service, not discounted when multiple
NCCI PTP pairs
103
100 hospital outpatient
LCDs and articles
7 / 8

TL;DR

G0399 is a Level II code from the G section (procedures and professional services, temporary), in use since 2008: "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". Hospital outpatient departments are paid $220.60 for G0399 under status indicator S, APC 5722 (Level 2 Diagnostic Tests and Related Services), minimum unadjusted copayment $44.12 (October 2026 Addendum B). MUE limits for G0399: practitioner 1 (MAI 2, Code Descriptor / CPT Instruction); hospital outpatient 1 (MAI 2, Code Descriptor / CPT Instruction). In the NCCI PTP files v323r0 G0399 appears in 11 practitioner pairs as column 2 and 92 as column 1 (most often with 95782, 95783, 95800), and in 11 hospital outpatient pairs as column 2 and 89 as column 1. 7 active LCDs and 8 billing and coding articles list G0399 across 29 states plus DC and 2 territories: L33405 (Polysomnography and Sleep Testing), L35050 (Outpatient Sleep Studies), A53019, A56903. HCPCS record: BETOS T2D (other tests - other); pricing indicator 13; type of service 5 (diagnostic laboratory). 1 other active code opens with "Home sleep test"; related codes: G0400, G0398, G0397, G0396.

G0399 descriptor and code status

The October 2026 HCPCS Level II file describes G0399 as “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 G section (procedures and professional services, temporary), listed with the other G codes. Although searches often call it the "G0399 CPT code", G0399 is a HCPCS Level II code maintained by CMS, not an AMA CPT code; both go in the same procedure-code field on the claim.

HCPCS file attributes of G0399
FieldValue
Short descriptorHome sleep test/type 3 porta
Added to HCPCS2008-03-13
Last actionN (no maintenance), effective 2008-03-13
Coverage codeC: carrier judgment, so the Medicare contractor decides coverage
Pricing indicator13: physician fee schedule, priced by the contractor
BETOS categoryT2D: other tests - other
Type of service5: diagnostic laboratory

Medicare payment for G0399

Hospital outpatient departments are paid $220.60 for G0399 under status indicator S, APC 5722 (Level 2 Diagnostic Tests and Related Services), minimum unadjusted copayment $44.12 (October 2026 Addendum B). The amounts below are national figures from the October 2026 CMS files; the contractor applies the locality, rural or state adjustment and the beneficiary's cost sharing.

Physician fee schedule (RVU26D)

Status C: contractor-priced: the MAC sets RVUs and payment case by case. Global period XXX (global surgery concept does not apply); PC/TC indicator 1 (diagnostic test with professional (26) and technical (TC) components).

G0399 also carries 26 and TC rows in the RVU file, priced separately from the global service.

Component rows for G0399
ModifierStatusNon-facilityFacility
26Cn/an/a
TCCn/an/a

Hospital outpatient (OPPS Addendum B)

Status indicator S (Procedure or service, not discounted when multiple), APC 5722 (Level 2 Diagnostic Tests and Related Services), national unadjusted payment $220.60 with a minimum unadjusted copayment of $44.12.

Medically Unlikely Edits for G0399

MUE limits for G0399: practitioner 1 (MAI 2, Code Descriptor / CPT Instruction); hospital outpatient 1 (MAI 2, Code Descriptor / CPT Instruction). The facility outpatient MUE is a date-of-service policy edit: units above the limit deny even when split across lines, and appeals rarely succeed.

MUE values for G0399 by setting
SettingMUE (units/DOS)MAICMS rationale
Practitioner services12 Date of Service Edit: PolicyCode Descriptor / CPT Instruction
Facility outpatient hospital12 Date of Service Edit: PolicyCode Descriptor / CPT Instruction

The MUE lookup for G0399 shows every setting next to any other code on the same claim.

NCCI edits and add-on rules

In the practitioner PTP file v323r0, G0399 is the column-2 (bundled) code in 11 active pairs, 0% of which allow a modifier and the column-1 code in 92 (54% modifier-allowed); 22 earlier pairs have been deleted. CMS's most frequent rationale for the bundled pairs: Mutually exclusive procedures.

Column-1 codes most often paired with G0399 (practitioner)
Column-1 codePairs
95782 (CPT; descriptor licensed by AMA)1
95783 (CPT; descriptor licensed by AMA)1
95800 (CPT; descriptor licensed by AMA)1
95801 (CPT; descriptor licensed by AMA)1
95805 (CPT; descriptor licensed by AMA)1
95806 (CPT; descriptor licensed by AMA)1
95807 (CPT; descriptor licensed by AMA)1
95808 (CPT; descriptor licensed by AMA)1
Column-2 codes bundled into G0399 (practitioner)
Column-2 codePairs
0733T (CPT; descriptor licensed by AMA)1
0903T (CPT; descriptor licensed by AMA)1
0904T (CPT; descriptor licensed by AMA)1
0905T (CPT; descriptor licensed by AMA)1
0937T (CPT; descriptor licensed by AMA)1
0938T (CPT; descriptor licensed by AMA)1
0939T (CPT; descriptor licensed by AMA)1
0940T (CPT; descriptor licensed by AMA)1

In the hospital outpatient PTP file v323r0, G0399 is the column-2 (bundled) code in 11 active pairs, 0% of which allow a modifier and the column-1 code in 89 (94% modifier-allowed); 22 earlier pairs have been deleted. CMS's most frequent rationale for the bundled pairs: Mutually exclusive procedures.

Column-1 codes most often paired with G0399 (hospital outpatient)
Column-1 codePairs
95782 (CPT; descriptor licensed by AMA)1
95783 (CPT; descriptor licensed by AMA)1
95800 (CPT; descriptor licensed by AMA)1
95801 (CPT; descriptor licensed by AMA)1
95805 (CPT; descriptor licensed by AMA)1
95806 (CPT; descriptor licensed by AMA)1
95807 (CPT; descriptor licensed by AMA)1
95808 (CPT; descriptor licensed by AMA)1
Column-2 codes bundled into G0399 (hospital outpatient)
Column-2 codePairs
0733T (CPT; descriptor licensed by AMA)1
0903T (CPT; descriptor licensed by AMA)1
0904T (CPT; descriptor licensed by AMA)1
0905T (CPT; descriptor licensed by AMA)1
0937T (CPT; descriptor licensed by AMA)1
0938T (CPT; descriptor licensed by AMA)1
0939T (CPT; descriptor licensed by AMA)1
0940T (CPT; descriptor licensed by AMA)1

G0399 is neither an add-on code nor a designated primary code in the 2026 Q4 NCCI add-on edit file.

Pair counts show exposure, not the answer for one claim. Check G0399 against a second code to see whether the pair bundles and whether a modifier can separate the services.

Medicare coverage policies for G0399

7 active Local Coverage Determinations and 8 billing and coding articles list G0399. Each applies only in its contractor's jurisdiction, and the article carries the diagnosis codes that support the item or service.

Billing and Coding Articles listing G0399
ArticleTitleContractor(s)Related LCD
A53019Polysomnography and Sleep Studies – Medical Policy ArticleWellpoint Federal—
A56903Billing and Coding: Polysomnography and Other Sleep StudiesWisconsin Physicians Service Insurance CorporationL36839
A56923Billing and Coding: Outpatient Sleep StudiesNovitas Solutions, Inc.L35050
A56995Billing and Coding: PolysomnographyPalmetto GBAL36593
A57049Billing and Coding: Polysomnography and Other Sleep StudiesCGS Administrators, LLCL36901, L36902
A57496Billing and Coding: Polysomnography and Sleep TestingFirst Coast Service Options, Inc.L33405, L36222
A57697Billing and Coding: Polysomnography and Other Sleep StudiesNoridian Healthcare Solutions, LLCL36861
A58559Billing and Coding: Independent Diagnostic Testing Facilities (IDTF)Palmetto GBA—

Denials to expect on G0399

the diagnosis or documentation does not meet the LCD or billing article that lists G0399

units of G0399 exceed the facility outpatient MUE of 1 per date of service

the 26 or TC modifier does not fit the component billed

the claim lacks the description, invoice or pricing detail a contractor-priced code needs

Where QuickIntell fits for G0399 claims

QuickCode supports qualified coder review of units, modifiers and NCCI pairs for G0399 before the claim leaves, and QuickRCM carries claim readiness and the denial follow-up when an edit or coverage policy is missed.

Frequently asked questions: HCPCS G0399

What does HCPCS code G0399 describe?

"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"), in the G section (procedures and professional services, temporary). Added 2008-03-13.

Is G0399 a CPT code?

No: CMS maintains G0399 in HCPCS Level II, while the AMA maintains CPT. People do search "G0399 CPT code", and it goes in the same procedure-code field.

What does Medicare pay for G0399?

Hospital outpatient departments are paid $220.60 for G0399 under status indicator S, APC 5722 (Level 2 Diagnostic Tests and Related Services), minimum unadjusted copayment $44.12 (October 2026 Addendum B).

How many units of G0399 can be billed per day?

MUE limits for G0399: practitioner 1 (MAI 2, Code Descriptor / CPT Instruction); hospital outpatient 1 (MAI 2, Code Descriptor / CPT Instruction). For the facility outpatient MUE (MAI 2), units above 1 deny for the whole day as a policy limit; denials arrive as CARC 151.

Does Medicare cover G0399?

Coverage code C (carrier judgment, so the Medicare contractor decides coverage). 7 active LCDs and 8 billing and coding articles list G0399 across 29 states plus DC and 2 territories: L33405 (Polysomnography and Sleep Testing), L35050 (Outpatient Sleep Studies), A53019, A56903.

Sources

Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-10. Verify against the primary file before billing or contracting decisions. The reference methodology explains how each figure is computed from these files.

Disclaimer

This page is an operational reference compiled from CMS publications: the HCPCS Level II file, the physician, DMEPOS and clinical laboratory fee schedules, OPPS and ASC addenda, NCCI MUE, PTP and add-on edit tables and the Medicare Coverage Database. Amounts are Medicare national figures before locality and state adjustment; Medicaid and commercial payers set their own. CPT codes are shown as numbers only; CPT descriptors are copyright AMA. Nothing here is legal, clinical or billing advice.

Found a figure that does not match the CMS file? Report a data correction with the CMS file and the value you expected; the request reaches the editorial team through the contact form.