S9992: The billing code for clinical trial travel and local rides
Overview
S9992 is the HCPCS code for transportation costs to and from a clinical trial location, plus local fares such as a taxi or bus, for the participant and one caregiver or companion. It is a private-payer S code that Medicare does not pay, and two large commercial plans list it as not covered. A ride company working with a study usually invoices the research site instead.
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What S9992 describes
S9992 is a travel code, not a ride code. Its full description in the October 2026 HCPCS file reads: “Transportation costs to and from trial location and local transportation costs (e.g., fares for taxicab or bus) for clinical trial participant and one caregiver/companion.”
That wording covers two kinds of cost. The first is getting to and from the place where the study runs, which can mean a flight or a long drive. The second is getting around locally once there, such as taxi or bus fares between a hotel and the research site. The code counts the participant plus one caregiver or companion, and no more.
S9992 sits in a small family of HCPCS codes for clinical trials:
- S9988, S9990 and S9991. Services provided as part of a phase I, phase II or phase III clinical trial.
- S9994. Lodging costs, such as hotel charges, for the participant and one companion.
- S9996. Meals for the participant and one companion.
How sponsors and research sites book and pay for study rides is covered in the guide to clinical trial patient transportation.
Who can pay an S code
S codes belong to private payers. CMS’s HCPCS coding procedures describe them as codes used mainly by private insurers to meet private-sector needs, which Medicaid programs may also use, and which Medicare does not pay. The October 2026 file repeats this for S9992 with coverage code I (not payable by Medicare) and processing note 0088, which says S codes were established by the Blue Cross Blue Shield Association and the Health Insurance Association of America for private payer use. S0215, a mileage code some Medicaid programs use, comes from the same family.
A code existing does not mean anyone covers it. CMS states that HCPCS Level II is not a method for deciding coverage or payment, and that a code’s existence does not settle whether an item or service is covered.
How two commercial plans treat S9992
Two large commercial insurers publish policies that name S9992, and both list it as not covered.
- UnitedHealthcare. The Clinical Trials medical policy for commercial and individual exchange plans (MP.006.27, effective September 1, 2026) puts S9992, S9994 and S9996 under “Not Covered.” Its exclusions list travel and transportation expenses, naming fees for personal vehicle, taxi, medical van, ambulance, commercial airline and train trips, plus rental cars, mileage reimbursement, lodging and meals. The phase codes S9988, S9990 and S9991 are listed as covered when criteria are met.
- Aetna. Clinical Policy Bulletin 0466 (last reviewed July 1, 2026) covers routine patient care costs in qualifying trials and lists S9992, S9994 and S9996 among the HCPCS codes not covered.
UnitedHealthcare’s policy adds that the member’s plan document and applicable law decide coverage, and that law may require coverage of a specific service. So a covered trip is possible under some plans. It just cannot be assumed.
Invoice the study, not the plan
S9992 is a code for claims, but a ride the study pays for is billed on an invoice. Your customer is the research site or the patient travel company the sponsor hired, under your agreement with them. FDA guidance says reimbursing a participant’s travel to and from the trial site, along with costs such as parking and lodging, does not raise undue influence concerns. The facility billing guide covers invoice terms with an organization that pays for riders, and the clinical trial transportation guide covers when a Medicaid member’s study visit goes through Medicaid instead.
Running study rides
HealthRide keeps each trip’s pickup and drop-off times, signatures and GPS-recorded miles with the ride, so every invoice line traces back to a real trip. Invoices go to the research site or travel company with that payer’s rates and payment terms, and payments by check, card or ACH are recorded against them.
Frequently asked questions
- Does Medicare pay for S9992?
- No. The October 2026 HCPCS file marks S9992 with coverage code I, not payable by Medicare, and with a note that S codes were set up for private payers and are neither valid nor payable by Medicare. A ride to a trial visit for a Medicare patient is paid by the study, the patient, or another coverage the patient has.
- Does S9992 cover a family member who rides along?
- One person, yes. The code description covers the clinical trial participant and one caregiver or companion. A second companion falls outside the description, so a plan or study that pays for more than one escort sets that rule in its own policy or budget.
- What are S9994 and S9996?
- They are the sister codes for the rest of a trial trip. S9994 is lodging costs, such as hotel charges, and S9996 is meals, each for the participant and one caregiver or companion. Both carry the same Medicare status as S9992, and both appear next to it on the commercial policies that list it as not covered.
- Can a transportation company bill a health plan with S9992?
- Only when the plan covers it, and the two large commercial policies that name it treat it as not covered. UnitedHealthcare also excludes travel and transportation from its clinical trial benefit, while saying the member's plan document and applicable law decide coverage. Ask the plan before the ride. When the study pays for the ride instead, the bill goes to the research site or the travel company the sponsor hired.
