A0100: Taxi billing code for NEMT
A0100 is the HCPCS code for non-emergency transportation by taxi. It is not the ambulatory van code. Colorado and South Dakota pay it per one-way trip and bill mileage on a separate S0215 line. Medicare does not pay it. Base rates vary widely: Colorado pays $12.15 a trip from July 1, 2026, and New York City $22.97, before mileage.
On this page
The official A0100 descriptor
The CMS HCPCS file for October 2026 lists A0100 as “Non-emergency transportation; taxi.” The code has been in HCPCS since 1982. It carries Medicare coverage code I, not payable by Medicare. Nothing in the descriptor sets a unit, so each payer decides whether A0100 is paid per trip, per mile, or by some other measure.
What A0100 covers
A0100 is for a ride in a taxi run by a licensed taxicab company. Colorado, for example, requires taxicab providers to hold a common carrier certificate with taxicab authority. The code is often confused with the ambulatory van code. Colorado’s manual draws the line: a taxi is not a mobility vehicle, and a taxi company that also holds a mobility permit bills A0120 when it operates under that permit. Oregon’s provider guide lists sedans and taxis together under A0100.
Wheelchair trips have their own base code, A0130, and it pays more. Colorado pays $34.14 for a wheelchair van leg against $12.15 for a taxi leg.
In Colorado and South Dakota, A0100 is a base rate for one leg. All four programs below bill miles on a second line, and the mileage code depends on the state.
How four states pay A0100
| State | A0100 base | Mileage line | Date |
|---|---|---|---|
| Colorado | $12.15 per one-way trip, down from $36.40 | S0215 at $2.74 a mile | Effective July 1, 2026 |
| Illinois | $2.66 in Cook and most counties; $6.40 in Madison and St. Clair | A0425 at $0.91 a mile ($1.61 in Madison and St. Clair) | Effective January 1, 2026 |
| New York | Set by county: $22.97 in New York City, $7.36 in Erie | S0215 at $2.93 a mile in New York City, $2.66 in Erie | Fee schedule dated April 5, 2026; these rates took effect in 2022 |
| South Dakota | $5.20 per one-way trip; $2.60 for each additional rider with TK | S0215 at $1.04 a mile, only outside city limits on trips of 21 miles or more one way | Effective July 1, 2026 |
A few details change the math. Colorado caps A0100 at two round trips per day and counts one unit per leg. Before July 1, 2025, Colorado taxi mileage went on A0425, and that code now applies only to ambulance trips. New York prices A0100 by county and by modifier, so the modifier on the line changes the payment. In New York, taxi and livery trips that start in, end in, or enter the Manhattan congestion zone carry a state surcharge. Providers bill it back under A0170 with TU ($2.75 for a single trip) or TK ($0.75 per person on a pool trip). The ancillary codes page covers that line.
Taxi billing mistakes to avoid
- Using A0100 for an ambulatory van. In Colorado, a taxi company operating under a mobility permit bills the mobility code, A0120.
- Billing a round trip as one unit. In per-leg programs, a round trip is two units of A0100.
- Keeping an old mileage code. Colorado claims with A0425 on a taxi line for dates after June 30, 2025 do not match the current manual.
- Billing mileage on short in-town trips. South Dakota pays no taxi mileage inside city limits.
States choose their own codes and rates, and brokers can add their own claim formats on top. For every code in one list, see NEMT billing codes. For the full claim process, see how to bill Medicaid for NEMT.
Frequently asked questions
- Is A0100 the code for ambulatory NEMT?
- Not usually. A0100 is the taxi code. Colorado, Illinois, and Medi-Cal bill ambulatory van or car service under A0120, and Louisiana and Texas use T2003. Colorado says outright that a taxi is not a mobility vehicle, and a taxi company running under a mobility permit bills the mobility codes and rates. Oregon is an exception that lists sedans and taxis together under A0100.
- How many units is a round trip under A0100?
- Two, in programs that pay per leg. Colorado's billing manual says one unit of A0100 equals one leg, so a round trip to an appointment and back is two units. Colorado also caps A0100 at two round trips per day.
- What mileage code goes with A0100?
- It depends on the payer. Colorado and New York use S0215. Illinois uses A0425. South Dakota pays S0215 only on trips outside city limits of 21 miles or more one way. Check the fee schedule, because a mileage line with the wrong code is denied.
