A0120: Ambulatory van and mini-bus billing code
A0120 is the HCPCS code for non-emergency transportation by mini-bus, mountain area transports, or other transportation systems. Colorado, Illinois, and Medi-Cal use it as the base rate for an ambulatory van or service car trip, billed per one-way leg with mileage on a separate line. Medicare does not pay it. Illinois pays $20 a trip, California up to $17.65, and Colorado $12.15.
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The official A0120 descriptor
The CMS HCPCS file for October 2026 describes A0120 as “Non-emergency transportation: mini-bus, mountain area transports, or other transportation systems.” It has been in HCPCS since 1982, and its Medicare coverage code is I, not payable by Medicare. The phrase “other transportation systems” makes it the broadest vehicle code in the series, and states use it for several different services.
What A0120 covers in practice
In Colorado, Illinois, and California, A0120 is the base rate for an ambulatory trip in a van or car that is not a taxi and not a wheelchair van. The rider walks on, sits in a regular seat, and rides to a covered appointment. The unit is one trip, and in Colorado, California, and South Dakota that means one one-way leg. Mileage goes on its own line, often as S0215, though the mileage code varies by state.
States do not agree on the details. Oregon uses A0120 for city bus transit, bus tickets, and passes. Louisiana pays its standard trip under T2003, and A0120 does not appear on Louisiana’s NEMT fee schedule at all. Texas bills every demand response ride under T2003, from taxis to wheelchair vans.
How four states pay A0120
| State | A0120 use and rate | Mileage | Date |
|---|---|---|---|
| California (Medi-Cal) | Base rate for all nonmedical transportation (NMT) trips: $17.65 maximum, $23.78 with UJ at night | A0390 at $1.30 a mile | Rates page updated August 2020 |
| Colorado | Mobility or ambulatory vehicle base: $12.15 per one-way trip, down from $36.40 | S0215 at $2.74 a mile | Effective July 1, 2026 |
| Illinois | Service car base: $20 in every county | A0425 at $1.03 a mile in Cook and the collar counties, $0.80 in most others | Effective January 1, 2026 |
| South Dakota | Mini-bus or other system: $5.20 in city, $7.80 with TN outside city limits | S0215 at $1.04 a mile on trips of 21 miles or more outside city limits | Effective July 1, 2026 |
Arizona’s AHCCCS pays A0120 at $6.64 urban and $7.27 rural with TN from October 1, 2026.
Each program adds rules on top. Medi-Cal caps A0120 at eight units per month, with an override when documentation shows the ride was needed for covered care. Colorado retired its old local mobility van codes and now bills A0120 with modifier TK, using units to show how many riders were on board. Colorado also adds modifier 76 to repeat trips for one member on the same day with the same provider, and 77 when the provider differs. South Dakota pays up to four one-way trips per member per day, and the second claim line carries modifier 59.
Billing pitfalls with A0120
- Mixing up wheelchair and ambulatory codes. Colorado pays wheelchair van codes only with a written statement that the member is wheelchair-confined. Without that statement, the wheelchair van bills A0120.
- One line for a busy day. South Dakota wants a second line with modifier 59 when a member visits several providers, and Colorado wants 76 or 77 on repeat trips.
- Wrong mileage code. Medi-Cal pairs NMT with A0390, Illinois with A0425, and Colorado with S0215.
- Ignoring the monthly cap. Medi-Cal claims past eight units need the documentation.
Because the same code means a van in one state and a bus pass in another, read the state manual before your first claim. The NEMT billing codes guide lists every code, and how to bill Medicaid for NEMT walks through the claim. For the vehicle type itself, see ambulatory transportation.
Frequently asked questions
- Is A0120 the ambulatory NEMT code?
- In several programs, yes. Colorado bills mobility and ambulatory vehicles under A0120, Illinois uses it for its service car base rate, and Medi-Cal uses it for all nonmedical transportation trips. Louisiana and Texas bill their standard trips under T2003 instead, so check the payer's code list.
- How do I bill extra riders on an A0120 trip?
- It depends on the state. Colorado bills A0120 with modifier TK and uses the number of units to show the actual number of riders. South Dakota pays a lower additional-recipient rate with TK. Medi-Cal uses per-patient modifiers UN through US when riders share the same origin and destination.
- Is there a monthly limit on A0120?
- In California, yes. Medi-Cal limits A0120 to eight units per month. The limit can be overridden with documentation that the member needed the ride for covered medical, mental health, substance use, or dental care.
