Q0 HCPCS Level II modifier: Investigational clinical service provided in a clinical research study that is in an approved clinical research study
Q0 is a HCPCS Level II modifier: “Investigational clinical service provided in a clinical research study that is in an approved clinical research study.” It adds this detail to the code it is reported with.
Official description
Q0Investigational clinical service provided in a clinical research study that is in an approved clinical research study
Short description: Invest clinical research
HCPCS · United States
Notes for Q0
As CMS prints them, with any note Q0 takes from the headings above it.
Note
- CMS processing note 0146: NCD MANUAL, SECTION 310.1, 42 CFR 405.205, SUBPART B SECTION 1862(A) OF THE ACT.
Medicare details
The indicators CMS publishes with Q0 in its October 2026 file. They describe Medicare’s handling, not another payer’s.
- Medicare coverage
- Special coverage instructions apply
- Added
- Jan 1, 2008
Where Q0 sits
- 1GroupHCPCS modifiers
- 2Modifier Q0Investigational clinical service provided in a clinical research study that is in an approved clinical research study
Source and release
- Data release
- HCPCS Level II · October 2026
- Effective date
- Oct 1, 2026
- Publisher
- CMS
This page is built from the HCPCS Level II catalog that Vero Codes reads when it suggests codes: Centers for Medicare & Medicaid Services’s October 2026 release, imported from the publisher’s file and checked against it. The description, notes and structured data come from the same record.
Frequently asked questions
What does HCPCS code Q0 mean?
Q0 is the HCPCS code for “Investigational clinical service provided in a clinical research study that is in an approved clinical research study” in CMS’s HCPCS Level II October 2026 release.
Where is Q0 in the HCPCS Level II list?
Q0 is listed under Modifiers.
Does Medicare cover Q0?
CMS lists Q0’s Medicare coverage as “Special coverage instructions apply”. Coverage and payment still depend on the patient, the setting, the documentation and the payer.
Which HCPCS Level II release does this page use?
It uses CMS’s October 2026 release, in effect from Oct 1, 2026 to Dec 31, 2026. It is a reference: confirm the code against the current list and the payer’s rules before you submit it.
Codes beside Q0
All modifiersPLProgressive addition lensesPMPost mortemPNNon-excepted service provided at an off-campus, outpatient, provider-based department of a hospitalPOExcepted service provided at an off-campus, outpatient, provider-based department of a hospitalPSPositron emission tomography (pet) or pet/computed tomography (ct) to inform the subsequent treatment strategy of cancerous tumors when the beneficiary's treating physician…PTColorectal cancer screening test; converted to diagnostic test or other procedureQ1Routine clinical service provided in a clinical research study that is in an approved clinical research studyQ2Demonstration procedure/serviceQ3Live kidney donor surgery and related servicesQ4Service for ordering/referring physician qualifies as a service exemptionQ5Service furnished under a reciprocal billing arrangement by a substitute physician or by a substitute physical therapist furnishing outpatient physical therapy services in a…Q6Service furnished under a fee-for-time compensation arrangement by a substitute physician or by a substitute physical therapist furnishing outpatient physical therapy services in…