A0424: the extra attendant code, and the Medicaid programs that pay it on rides

A0424 is a crew code, not a rider code. The HCPCS descriptor reads “Extra ambulance attendant, ground (ALS or BLS) or air (fixed or rotary winged); (requires medical review).” CMS’s October 2026 file shows it was added on January 1, 1995 and marks it coverage code I, not payable by Medicare, so any payment comes from a Medicaid program or a plan. It adds a crew member to an ambulance trip, such as one billed with A0428, and it does not replace the code for a family escort, which is covered in escorts and attendants.

Which programs pay A0424

Ohio, Oregon and Indiana pay it. New Mexico does not pay it fee-for-service.

Ohio’s rate has not changed since January 1, 2024. Oregon’s has stood since September 1, 2012. Indiana’s is the rate effective January 1, 2026, up from $6.48 in 2025. These rates sit beside each state’s wheelchair van and ambulance codes in the Ohio, Oregon and Indiana rate guides.

Extra attendant or escort

An escort rides with the member, and an extra attendant works for you. Indiana separates the two in its billing module. An accompanying adult or attendant is billed on the member’s claim, with T2001 for commercial ambulatory trips and a TK modifier on wheelchair van and taxi trips. An additional attendant helps load a member when the driver cannot, for example when a wheelchair user lives upstairs and there is no ramp. That person must be an employee of the billing provider.

The IHCP limits additional attendants to two extra units, and the module notes that one is usually enough. A wheelchair van bills A0130 with U6, which pays $7.95 in 2026. An ambulance bills A0424, and Indiana says that attendant is the third or fourth, because the program requires two attendants on every ambulance.

Ohio treats its wheelchair van attendant as a separate line. Its appendix lists T2001 “Attendant, wheelchair van” at $15.00 beside the ambulance extra attendant at $18.00.

Showing the claim needs medical review

The descriptor says it, and each payer asks for something in writing. Ohio sends ambulance and wheelchair van claims to manual review unless the trip’s origin and destination are exempted in the appendix, and a review request includes a justification for the use of an attendant when applicable. Indiana wants the need for the additional attendant documented on the driver’s ticket, and it can review that documentation after payment. A note such as “second attendant needed to carry member down stairs, no ramp” is the kind of reason a reviewer can use.

Where you will meet it

A0424 belongs on ambulance claims, and some plans list it for wheelchair and gurney trips as well. IEHP’s billing guide lists A0424 as “Additional Attendants” under both its wheelchair and gurney services, and contract terms set the pay. If your company runs both vans and ambulances, check each payer’s schedule before you reuse a van code on an ambulance claim.

HealthRide records escorts and the assigned driver on each trip, so the people on a run are on the trip record.