Ambulance billing guide
Ambulance services are covered under Medicare when furnished to a Medicare beneficiary under the conditions listed below.
- Actual transportation of the beneficiary occurs.
- Beneficiary transported to an appropriate destination.
- Transportation by ambulance must be medically necessary, i.e., the beneficiary’s medical condition is such that other forms of transportation are medically contraindicated.
- Ambulance provider/supplier meets all applicable vehicle, staffing, billing, and reporting requirements.
Medicare ambulance coverage requirements
- The Code of Federal Regulations (CFR):
- CMS IOMs:
Ambulance trip/run sheet record documentation
The ambulance provider must have full documentary evidence to support the Medicare claim for ambulance services. Without documentation that would establish the medical necessity of a service, the service may be non-covered by Medicare, either as a denial prior to payment or a request for refund after an incorrect payment has been made.
Ambulance physician certification statement (PCS)
PCS are required for patients who are under the direct care of a physician and are required for:
- Scheduled non-emergency ambulance transports
- Unscheduled non-emergency ambulance transports
Claim filing requirement
Assignment of Benefits (AOB) beneficiary signature requirements
Medical records must substantiate the AOB to authorize the ambulance service provider to bill Medicare. The AOB must be signed by the beneficiary, or by a representative if the beneficiary is unable to sign. Additionally, the reason the beneficiary could not sign must be clearly documented in the medical record. Signature requirement outlined in CFR, Title 42, Chapter IV, Subchapter B, Part 424.36 - Signature Requirements
Dates of service
The date of service (DOS) for an ambulance service is the date the loaded ambulance vehicle departs the point of pickup.
In the case of a ground transport, if the beneficiary is pronounced dead after the vehicle is dispatched but before they are loaded into the vehicle; the DOS is the date of dispatch.
In the case of an air transport, if the beneficiary is pronounced dead after the aircraft takes off to pick up the beneficiary, the DOS is the date of the vehicle’s takeoff.
Note: You must report eight-digit dates in all date of birth fields. Providers have the option of entering six or eight-digit dates in all other fields. Dates should be consistent.
Round trips: When billing round trips, each trip will need to be submitted on a separate claim.
Ambulance modifiers
Providers and suppliers must report an origin and destination modifier for each ambulance trip provided. Origin and destination modifiers used for ambulance services are created by combining two alpha characters.
Each alpha character, except for “X”, represents an origin code or a destination code. The pair of alpha codes creates one modifier. The first position alpha code equals origin; the second position alpha code equals destination.
Supplies, drugs, and special services
Supplies, drugs and ancillary services (wait time, extra attendant, oxygen) are part of the transport and you cannot bill the patient.
Medicare will allow providers/suppliers to submit a claim for secondary benefit denials for the HCPCS codes A0021 through A0424 and A0998.
Modifier GY can be used for statutorily excluded services.
Units for mileage codes
Mileage can be allowed to the nearest appropriate facility when the ambulance transfer is covered. Only the actual number of “loaded” miles from the point of pickup to the point of destination can be reported as mileage.
Fractional mileage:
- Miles must be reported as fractional units.
- Round the total miles up to the nearest tenth of a mile and report the resulting number with the appropriate HCPCS code for ambulance mileage:
- Trips totaling 100 covered miles, and greater, report mileage rounded up to the next whole number mile without the use of a decimal (e.g., 998.5 miles should be reported as 999)
- Trips totaling less than one mile: Enter a “0” before the decimal (e.g., 0.9)
- Applies only to ambulance services billed on a Form CMS-1500 paper claim, ANSI X12N 837P or 837I electronic claims
Note: This does not apply to providers billing on the paper UB. The decimal must be used in the appropriate place (e.g., 99.9)
Part A institutional providers billing on the UB-04 or the electronic equivalent
Claim data elements
Type of bill:
You must report the appropriate type of bill. The most common TOBs for ambulance services are:
- 13X - outpatient hospital
- 22X - inpatient Part B ancillary (skilled nursing facility)
- 23X - outpatient skilled nursing facility
- 85X - outpatient CAH (critical access hospital)
Condition code:
Medically necessary ambulance services furnished by a critical access hospital (CAH), or an entity owned and operated by the CAH are paid based on 101% of the reasonable cost if the 35-mile rule for cost-based payment is met.
In order for the 35-mile rule to be met, the CAH or the entity that is owned and operated by the CAH, must be the only provider/supplier of ambulance services located within a 35-mile drive of the CAH or the entity.
Report condition code B2 if you meet the CAH 35-mile rule. Appending the condition code B2 (CAH ambulance attestation) indicates the CAH ambulance meets fee schedule exemption criteria to receive cost reimbursement.
Value code/amount:
Report value code 32 with the number of patients transported, when transporting more than one patient at a time to the same destination.
Report value code A0 along with the ZIP code identifying the point of pick-up.
Revenue code:
Report revenue code 0540 on the claim for ambulance services.
Line-item dates of service:
You must report the date of service on each revenue code line.
Report the number of loaded miles with HCPCs codes A0425, A0435 or A0436 (mileage must be reported as fractional units). You may round up/down to one decimal place.
Refer to MLN Medicare Billing: CMS-1450 & 837I booklet for information on submitting Part A claims.
Part B suppliers billing on the CMS-1500 claim form or electronic equivalent
Item 23:
Report the point of pickup ZIP code.
The five-digit point of pickup (POP) ZIP code is required on all claims and must be reported in Item 23 on the 1500 claim form or electronic equivalent of Item 23.
Suppliers utilizing the repetitive scheduled non-emergent ambulance transport (RSNAT) prior authorization process will need to review the claims submission guidelines for submitting the UTN for affirmed and non-affirmed claims
Refer to MLN Medicare Billing: 837P and Form CMS-1500 booklet for information on submitting Part B claims.