HCPCS Level II · Temporary national codes (non-Medicare)
S9991Services provided as part of a phase iii clinical trial
✓ Active
Source: CMS HCPCS quarterly update, October 2026. Page updated September 29, 2026.
About S9991
S9991 is an HCPCS Level II code in the S series (temporary national codes (non-Medicare)), describing services provided as part of a phase iii clinical trial.
It was added to HCPCS effective 01/01/2000.
Its Medicare coverage code is "I", meaning it is not payable by Medicare (another code or method is used).
Details
- Short description
- Services provided as part of
- Date added
- 01/01/2000
- Action effective
- 01/01/2000
- BETOS
- Z2
Related S99xx codes
- S9900Services by a journal-listed christian science practitioner for the purpose of healing, per diem
- S9901Services by a journal-listed christian science nurse, per hour
- S9960Ambulance service, conventional air service, nonemergency transport, one way (fixed wing)
- S9961Ambulance service, conventional air service, nonemergency transport, one way (rotary wing)
- S9970Health club membership, annual
- S9975Transplant related lodging, meals and transportation, per diem
- S9976Lodging, per diem, not otherwise classified
- S9977Meals, per diem, not otherwise specified
- S9981Medical records copying fee, administrative
- S9982Medical records copying fee, per page
- S9986Not medically necessary service (patient is aware that service not medically necessary)
- S9988Services provided as part of a phase i clinical trial
Common questions about S9991
Is HCPCS S9991 still valid?
- Yes. S9991 is active in the CMS October 2026 HCPCS file.
Does Medicare cover S9991?
- Its coverage code is "I": it is not payable by Medicare (another code or method is used). Check the local coverage determination for your region.