Billing codes
U Modifiers (U1 to UD) on Medicaid NEMT Claims: How States Use Them
U modifiers are the 13 HCPCS modifiers U1 to U9 and UA to UD, which CMS defines only as "Medicaid level of care, as defined by each state." Medicare does not pay them, and each Medicaid program gives them its own meaning. On NEMT claims they can mark the county type, the kind of rider, an extra attendant, a taxi distance band, or a bariatric van.
- U1 to U9 and UA to UD mean "Medicaid level of care 1 to 13, as defined by each state." CMS gives them no other meaning.
- The same letters mean different things by state: U3 is a suburban county in Texas, mileage or waiting time on an ambulatory trip in Indiana, and a wheelchair van service in an ambulance in Ohio.
- Texas pays T2003 U1 $33.83, U3 $62.31, and U2 $79.63 per leg from September 1, 2026.
- Other U modifiers, such as UJ for night and UN to US for two to six or more patients, keep one national meaning.
- Use only the code and modifier pairs your fee schedule lists for the date of service, or the line can deny.
What the U modifiers mean
A modifier is a two-character tag after a billing code. It changes what the line pays for without changing the code. Most HCPCS modifiers have one meaning everywhere. The U modifiers are the exception: CMS created 13 of them for Medicaid programs to define.
| Modifier | CMS description |
|---|---|
| U1 to U9 | Medicaid level of care 1 to 9, as defined by each state |
| UA | Medicaid level of care 10, as defined by each state |
| UB | Medicaid level of care 11, as defined by each state |
| UC | Medicaid level of care 12, as defined by each state |
| UD | Medicaid level of care 13, as defined by each state |
All 13 entered the code set on July 1, 2002. In the October 2026 HCPCS file they carry coverage code I, which means Medicare does not pay them. “Level of care” is only a label. The states below use U modifiers to price or flag a county type, a rider’s mobility, an extra helper, a distance band, or a larger van.
Other U modifiers look similar but keep one national meaning. You do not need your state to define these, though your state still decides whether it pays them.
| Modifier | National meaning |
|---|---|
| UE | Used durable medical equipment |
| UF, UG, UH | Services provided in the morning, afternoon, or evening |
| UJ | Services provided at night |
| UK | Services provided on behalf of the client to someone other than the client |
| UN, UP, UQ, UR, US | Two, three, four, five, or six or more patients served |
Medi-Cal is one program that uses the national ones on NEMT claims. Its wheelchair van base, A0130, pays $20.30 for one rider, $26.43 with UJ at night, and $16.22 per patient with UN when two ride together (rate page updated September 2023).
How states use U modifiers on NEMT claims
These are the U1 to UD meanings in four state fee-for-service programs, with the rates in effect in September 2026.
| State | Code and modifier | What it means there | Rate |
|---|---|---|---|
| Texas (Medical Transportation Program) | T2003 U1 | A one-way leg in a metro or urban county | $33.83 per leg, from September 1, 2026 |
| Texas | T2003 U3 | A leg in a micro or suburban county | $62.31 |
| Texas | T2003 U2 | A leg in a rural county | $79.63 |
| Indiana | A0425 U3 | Mileage on a commercial ambulatory trip, for riders who walk | $1.67 a mile, from January 1, 2026 |
| Indiana | A0425 U5 | Mileage on a nonambulatory (wheelchair van) trip | $1.67 a mile |
| Indiana | T2007 U3 or U5 | Waiting time on an ambulatory or wheelchair trip | $7.43 per half hour |
| Indiana | A0130 U6 | An extra attendant who helps load a wheelchair rider | $7.95 |
| Indiana | A0100 UA, UB, UC | A taxi trip of 0 to 5, 6 to 10, or 11 or more miles | $7.63, $12.71, $19.08 |
| Ohio | A0130, S0209, or T2001 with U3 | A wheelchair van service given in an ambulance vehicle | A0130 $31.00, S0209 $1.30 a mile (last changed January 1, 2024) |
| Ohio | U4 or U7, paired with a second two-character code for the other end of the trip | A workplace (U4) or a school (U7) as the pickup or drop-off point | Point modifier, no separate rate |
| Ohio | U5 | A pickup or drop-off point not otherwise listed, which always goes to manual review | Point modifier |
| Ohio | U6 | The health care service was unavailable when the vehicle arrived | Information modifier |
| Ohio | UA or UB | A second (UA) or third (UB) trip the same day, in the same type of vehicle, to or from the same type of place | Information modifier |
| Colorado | A0130 U9 | An XL or bariatric wheelchair van base rate, with two attendants for loading and unloading | $63.70 per one-way trip from July 1, 2026 ($65.00 from November 1, 2025) |
Indiana has already posted its 2027 rates, effective January 1, 2027: A0425 U3 and U5 rise to $1.72 a mile, T2007 U3 and U5 to $7.65, A0130 U6 to $8.18, and A0100 UA, UB, and UC to $7.85, $13.08, and $19.63.
Texas pays each leg once for every seat the program authorized, under TMHP’s July 20, 2021 notice. Indiana deducts the first 10 miles of each one-way ambulatory or wheelchair trip, but you still bill every mile. Ohio’s appendix, in effect since August 1, 2026, lists which pickup and drop-off pairs it pays without manual review. See origin and destination modifiers for how Ohio and Indiana pair the point letters.
The letters also turn up outside NEMT. Arizona’s fee-for-service manual (revised July 31, 2026) uses UA to UD on A0998 for ambulance treat-and-refer visits, such as UA for treat at home and refer to a primary care provider or specialist. UA alone means three different things in Indiana, Ohio, and Arizona.
A worked example: one Indiana wheelchair leg
A wheelchair van takes a member home from the hospital, 30 loaded miles. The member lives upstairs with no ramp, so a second employee meets the van to help get the member up the stairs. Indiana’s Transportation Services module (version 6.1) allows an extra attendant in that case, as long as the attendant works for the billing provider and the driver’s ticket records why the help was needed.
| Line | Code | Units billed | Paid |
|---|---|---|---|
| Base rate | A0130 | 1 | $31.79 |
| Extra attendant | A0130 U6 | 1 | $7.95 |
| Mileage | A0425 U5 | 30 | 20 miles after the 10-mile deduction × $1.67 = $33.40 |
| Total | $73.14 |
The same leg on or after January 1, 2027 pays $75.29: $32.71 for the base, $8.18 for the attendant, and 20 miles at $1.72.
Two details decide whether this pays. The mileage line uses A0425 with U5, because Indiana bills all ground mileage on A0425 and does not pay S0215. And Indiana wants an origin and destination modifier on the base and mileage lines, here HR for hospital to residence. On an ambulatory trip the same 30 miles would bill A0425 U3 at the same $1.67 rate.
For a fee-for-service member, a hospital discharge home is a trip Verida brokers, so the claim goes to Verida, not the state. Verida’s rates are based on the IHCP fee schedule, and each company signs a Verida rate agreement that lists them, so check yours before you count on these amounts.
How to find what your state’s U modifiers mean
- Open your fee schedule. Many list the modifier in its own column next to the code. Indiana’s professional fee schedule and Colorado’s NEMT fee schedule do, and Texas’s rate table explains its modifiers in a note: U1 metro, U2 rural, U3 micro.
- Read the transportation manual. The manual says when each modifier applies and what proof you keep, such as Indiana’s attendant note on the driver’s ticket.
- Check your broker’s rate sheet. Broker and health plan trips follow the broker’s codes, which may not match the state’s fee-for-service list. See NEMT billing codes for the base codes they build on.
- Keep the order your payer shows. Indiana writes taxi companions as A0100 UA TK, with the distance modifier first. Box 24D of the CMS-1500 holds up to four modifiers on each line. See the TK modifier for companion and extra rider billing.
- Match the date of service. Modifiers are added and retired. Colorado’s U9 rate started November 1, 2025, and a pair billed before its start date can deny with reason code 182, “Procedure modifier was invalid on the date of service.”
- Never carry a modifier across a state line. A U3 that pays in Texas means something else in Indiana and Ohio. A pair your payer does not list can deny with reason code 4, “The procedure code is inconsistent with the modifier used.”
Frequently asked questions
What does the U1 modifier mean in Medicaid?
CMS defines U1 only as "Medicaid level of care 1, as defined by each state," so the meaning depends on the program. In Texas's fee-for-service Medical Transportation Program, T2003 U1 is a trip in a metro or urban county, paid $33.83 per leg from September 1, 2026. Indiana lets ambulance providers add U1 or U2 to A0425 as information only.
Does Medicare accept U modifiers?
No. In the October 2026 CMS HCPCS file, U1 through UD carry coverage code I, which means not payable by Medicare. They have been in the national code set since July 1, 2002, for Medicaid programs to define. Each Medicaid program, and the plans and brokers that pay under it, decides how to use them.
Are UN through US modifiers state-defined too?
No. UN, UP, UQ, UR, and US have fixed national meanings: two, three, four, five, and six or more patients served. Medi-Cal uses them on shared wheelchair van rides, paying A0130 UN at $16.22 per patient against a $20.30 single-rider base (rate page updated September 2023). The state-defined group is only U1 to U9 and UA to UD.
Which modifier is used for a bariatric wheelchair van?
There is no national bariatric modifier. Colorado uses A0130 with U9 for an XL or bariatric wheelchair van base rate, paid $63.70 per one-way trip from July 1, 2026, and the trip must have two attendants for loading and unloading. Other states may use a different modifier or no bariatric rate at all, so check your fee schedule.
Can I add a U modifier my state does not list?
No. A U modifier only means something when your payer defines it for that code. An unlisted pair can deny with reason code 4, "The procedure code is inconsistent with the modifier used," or 182, "Procedure modifier was invalid on the date of service." Bill only the pairs on your fee schedule or broker rate sheet for the date of service.