What are U modifiers on Medicaid transportation claims?
U modifiers are 13 HCPCS modifiers, U1 to U9 and UA to UD, that CMS defines only as a Medicaid level of care "as defined by each state." Every state writes its own meanings. On ride claims, Texas uses U1 to U3 for the county type, Indiana uses U3 and U5 to separate ambulatory and wheelchair van miles, and Colorado adds U9 when an XL wheelchair rider needs two attendants.
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Thirteen modifiers with no national meaning
CMS lists 13 U modifiers in the HCPCS code set: U1 through U9, then UA, UB, UC, and UD. Each descriptor follows one pattern, from “Medicaid level of care 1, as defined by each state” to “Medicaid level of care 13, as defined by each state.” CMS added the whole set on July 1, 2002, and Medicare pays none of them (coverage code I).
The phrase “as defined by each state” is the whole point. Medicare’s claims manual says each state defines its own Medicaid coverage, payment, and utilization levels. A state uses U modifiers to split one national code into versions it can price or track separately. U3 in Indiana and U3 in Ohio have nothing to do with each other.
How four programs use them on rides
| Program | Code and modifier | What the state says it means |
|---|---|---|
| Texas | T2003 U1, U2, U3 | A trip in a metro or urban county (U1), a rural county (U2), or a micro or suburban county (U3). The September 1, 2026 rates per leg are $33.83, $79.63, and $62.31. |
| Indiana | A0425 U3 and U5; T2007 U3 and U5 | Mileage and waiting time for commercial ambulatory (U3) and non-ambulatory, or wheelchair, service (U5). U3 and U5 miles pay $1.67 against $9.15 for unmodified ambulance miles. |
| Indiana | A0100 UA, UB, UC; A0130 U6 | Taxi distance bands: UA up to 5 miles, UB from 6 through 10, UC beyond 10. U6 pays $7.95 for an extra attendant who helps the driver load a wheelchair van rider. |
| Colorado | A0130 U9 | XL wheelchair ride that uses two attendants to help the member in and out, covered since November 1, 2025. The July 1, 2026 rate is $63.70, against $34.14 for the regular A0130 base. |
| Nevada | Its listed transportation codes, from A0080 to T2005, with U1 or U2 | First leg (U1) and return leg (U2) of a pharmacy trip, in the state’s transportation encounter data. |
Texas also counts seats. When T2003 billing began in June 2021, TMHP said payment is figured by the number of seats authorized for each leg, so a leg authorized for two passengers pays the leg rate twice.
Ohio’s seven U modifiers
Ohio’s transportation payment appendix, enacted July 10, 2026, uses seven of the 13 modifiers, and only some of them describe a service:
- U3: wheelchair van service delivered in an ambulance. Ohio allows it on three codes only: A0130, S0209, and T2001.
- U4 and U7: a workplace and a school. They act as extra place letters beside the origin and destination modifiers. A ride from work to a practitioner’s office is written U4 with IP, because U4 needs a second two-letter pair.
- U5: an origin or destination not otherwise specified, which sends the claim to manual review.
- U6: the service was unavailable when the vehicle arrived at the destination.
- UA and UB: repeat trips. UA marks a person’s second trip of the day and UB a third, when the vehicle type and the kind of origin or destination match the first.
The same appendix lists which code, modifier, and trip pairings pass without manual review.
Reading your state’s U modifiers
- Find the modifier list. South Dakota publishes an Authorized Modifiers document with each modifier’s payment effect. Indiana keeps a modifier table on its Code Sets page. Ohio puts its list in the rule appendix.
- Match modifiers to codes. A U modifier only means something on the codes the state pairs it with. Check the fee schedule line, not just the list.
- Check the order. South Dakota requires payment-affecting modifiers to come first on the line.
- Watch the dates. Colorado corrected its XL wheelchair modifier from U1 to U9 in November 2025. Indiana stopped requiring U1 and U2 on ALS and BLS mileage from July 1, 2023.
- Ask each payer. Managed care plans and brokers inside the state program can write their own rules, so confirm with them before you copy the state’s list.
The TK modifier covers extra passengers, and our guide to NEMT billing codes lists the base codes these modifiers attach to. U modifiers often encode a level of service, as Indiana’s U3 and U5 do, so the rider’s level has to be right on the trip itself. HealthRide records each trip’s service level, from ambulatory to wheelchair or stretcher, and the dispatch board matches it to a vehicle that fits.
Frequently asked questions
- Does U1 mean the same thing in every state?
- No. The national descriptor for U1 is "Medicaid level of care 1, as defined by each state," so the meaning comes only from the state. In Texas, T2003 U1 is a trip in a metro or urban county. In Nevada's transportation encounter guide, U1 marks the first leg of a pharmacy trip. Indiana treats U1 on ambulance mileage as informational only.
- Does Medicare pay U modifiers?
- No. CMS gives all 13 coverage code I, not payable by Medicare, in its October 2026 file. State programs, along with the plans and brokers paying for them, use them to split one national code into the service levels or places a state wants to price separately.
- What happens if I leave off a U modifier my state requires?
- The line can price as something else or deny. In Indiana, A0425 with no modifier is reserved for ALS and BLS ambulance miles at $9.15 a mile, while ambulatory and wheelchair van miles need U3 or U5 and pay $1.67. In Texas, the September 2026 fee schedule for demand response providers prices T2003 only with U1, U2, or U3, and shows no rate for the bare code.
