G0378 HCPCS code: Hospital observation service, per hour

G0378 is the HCPCS Level II code for hospital observation service, per hour. Its Medicare coverage code is D (Special coverage instructions apply): Medicare covers it when its national or local coverage criteria are met. The NCCI unit limit is 72 per day on outpatient hospital claims.

Code details

NCCI unit limits (MUE)

Medicare policy articles for this code

• A56673: Billing and Coding: Outpatient Observation Bed/Room Services (Palmetto GBA (MAC - Part A))

Covered diagnoses (1 ICD-10-CM codes)

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

What changed for G0378

• 2006-01-01: G0378 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 G0378?

G0378 is the HCPCS Level II code for hospital observation service, per hour. Short descriptor: "Hospital observation per hr".

Does Medicare cover G0378?

Coverage code D — Special coverage instructions apply. Medicare covers it when its national or local coverage criteria are met.

Which diagnoses support coverage for G0378?

Medicare policy articles that cite G0378 list 1 covered ICD-10-CM diagnosis codes across 1 article. The most cited include XX000 (Not Applicable). A listed diagnosis is necessary but not sufficient; the policy's other criteria still apply.

How many units of G0378 can be billed per day?

72 on outpatient hospital 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 G0378
• Watch G0378 for fee, coverage and descriptor changes
• Build a full Medicare revenue model for G0378

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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