Medicare Ambulance Billing Guide

Medicare covers ground ambulance services under Part B. A transport is covered when three things are true: the patient’s condition made any other means of transportation unsafe, the service was reasonable and necessary, and the patient was taken to an appropriate destination, generally the nearest facility able to provide the care they needed. Each of these has to be supported by the run report and, for many non-emergency trips, by a Physician Certification Statement.

Emergency and non-emergency transports

Medicare treats a response as an emergency when the ambulance responds immediately to a 911 call or its equivalent. Emergency transports still need documentation of the patient’s condition, but they do not require a PCS.

Non-emergency transports face closer review. Medicare often looks at whether the patient was bed-confined, which means all three of the following: unable to get up from bed without assistance, unable to walk, and unable to sit in a chair or wheelchair. Bed confinement is not the only way to show medical necessity, and it does not guarantee coverage on its own. The narrative still has to explain why other transport would have been unsafe.

Physician Certification Statements (PCS)

• Scheduled, repetitive non-emergency transports (for example, recurring dialysis trips) need a PCS signed by the patient’s attending physician, dated no earlier than 60 days before the transport.
• Unscheduled non-emergency transports need a PCS obtained within 48 hours after the transport. It can be signed by the attending physician or, if unavailable, by another qualified professional such as a physician assistant, nurse practitioner, clinical nurse specialist, registered nurse, or discharge planner with knowledge of the patient’s condition.
• If a signed PCS cannot be obtained, Medicare allows the claim to be submitted after documented attempts, such as a signed return receipt showing the request was mailed at least 21 days before the claim was submitted.

A PCS supports medical necessity, but it does not replace the crew’s documentation. Medicare has also run a prior authorization model for repetitive, scheduled non-emergent transports in some states, so check with your Medicare Administrative Contractor whether it applies to you.

How Medicare calculates payment

Payment has two parts: a base rate for the level of service and a mileage payment for loaded miles.

• Base rate: each level of service has a relative value unit (1.00 BLS non-emergency, 1.60 BLS emergency, 1.20 ALS1 non-emergency, 1.90 ALS1 emergency, 2.75 ALS2, 3.25 SCT). The RVU is multiplied by an annual conversion factor, and part of the amount is adjusted for local costs.
• Mileage: billed per loaded mile with A0425. Rural pickups receive an increased rate for the first 17 loaded miles.
• Add-ons: temporary increases of 2% for urban, 3% for rural, and 22.6% for super-rural pickups, based on the ZIP code where the patient was picked up.
• Patient share: after the Part B deductible, the patient generally owes 20% coinsurance. Ambulance providers and suppliers must accept Medicare assignment.

For the 2026 add-ons and the ZIP code changes proposed for 2027, see our Medicare Ambulance Fee Schedule 2026 article. For codes and modifiers, see our ambulance billing codes guide.

Advance Beneficiary Notices (ABN)

For non-emergency transports that Medicare may not cover, an ABN lets the patient decide in advance whether to accept financial responsibility. An ABN cannot be issued in an emergency. When a valid ABN was issued, the claim carries the GA modifier.

Signatures

Medicare generally requires the patient’s signature authorizing the claim. When the patient is physically or mentally unable to sign, Medicare allows specific alternatives, such as an authorized representative, or a crew member statement supported by documentation from the receiving facility. Record why the patient could not sign.

Filing and appeals

Claims must be filed within 12 months of the date of service. If a claim is denied, Medicare has five appeal levels:

1. Redetermination by the Medicare Administrative Contractor, requested within 120 days of the initial determination
2. Reconsideration by a Qualified Independent Contractor, within 180 days of the redetermination
3. Administrative Law Judge hearing, within 60 days, if the amount in controversy meets the threshold
4. Medicare Appeals Council review, within 60 days
5. Federal district court review, within 60 days, if the amount in controversy meets the threshold

Data collection (GADCS)

Medicare selects a sample of ground ambulance organizations each year to report cost and revenue data through the Ground Ambulance Data Collection System. Selected organizations that do not report can face a 10% payment reduction for a year.

Medicare ambulance billing checklist

• Narrative explains why other transport was unsafe
• Level of service matches documented care
• Origin and destination modifier matches the run
• Loaded mileage reported to the nearest tenth under 100 miles
• PCS on file for non-emergency transports, within the required time
• Patient signature or a documented exception
• ABN issued where appropriate for non-emergency trips
• Claim filed well within 12 months

Our ambulance billing services and EMS denial management teams apply these rules on every Medicare claim.