Emergency Transport Mileage & the Loaded-Mile Billing Rule (2026)

What is the "loaded-mile rule" and where does it come from?

When an ambulance crew responds to a call, the vehicle travels in three distinct phases: from the garage or station to your location (unloaded), from your location to the hospital with you on board (loaded), and from the hospital back to base (unloaded again). The loaded-mile rule says only the middle segment — the stretch where you were physically inside the vehicle — can be billed to you or your insurer.

Under 42 CFR § 414.605, CMS defines loaded mileage as "the number of miles the Medicare beneficiary is transported in the ambulance vehicle." Medicare payment for ambulance services is based on the lesser of the actual charge or the applicable fee schedule amount, and the fee schedule payment equals a base rate for the level of service plus payment for mileage and applicable adjustment factors.

The CMS Medicare Claims Processing Manual (Pub. 100-04, Chapter 15) states that charges for mileage must be based on loaded mileage only — from the pickup of a patient to arrival at destination. It presumes that all unloaded mileage costs are taken into account when a supplier establishes its basic charge for ambulance services and its rate for loaded mileage, and that separate charges for unloaded mileage will be denied. That last point is critical for patients: if you see a line item on your bill that appears to represent the crew driving to your location, that charge is not payable under Medicare rules and should be disputed.

Per the CMS Internet Only Manual (IOM), Publication 100-02, Chapter 10, Section 10.3, "as a general rule, only local transportation by ambulance is covered, and therefore, only mileage to the nearest appropriate facility equipped to treat the patient is covered." This means that even if the crew drove you to a hospital farther away — say, because it's your preferred facility — only the distance to the nearest appropriate facility is reimbursable under Medicare. Any excess mileage beyond that threshold may be billed to you separately, or it may represent a billing error if the provider cannot document why the closer facility was bypassed.

Which HCPCS codes carry the mileage charge on your bill?

Ambulance bills arrive with two distinct categories of charges: a base-rate code for the level of care provided and a separate mileage code for the distance traveled. When you pull your itemized bill or review every line on your itemized hospital bill, look for both types.

HCPCS code A0425 is the valid 2026 code for ground mileage, per statute mile, used in ambulance billing. Only the actual number of "loaded" miles from the point of pickup to the point of destination can be reported as mileage. Covered air ambulance mileage is paid when the appropriate HCPCS code is reported: A0435 identifies fixed-wing air mileage and A0436 identifies rotary-wing air mileage.

One technical detail worth knowing: ambulance services must be reported with an origin and destination modifier for each ambulance trip. These two-letter modifiers (for example, "SH" for scene-to-hospital) tell the insurer where the trip started and ended. If the modifier on your bill doesn't match your experience — say, it shows hospital-to-hospital when you were transported from your home — that is a flag worth questioning. You can see how providers sometimes split this into two separate invoices by reading our guide on why one visit can generate two bills.

How are mileage rates calculated — and what affects what you owe?

The ambulance fee schedule has two components: a base payment and a mileage payment, which are summed to arrive at the total Medicare payment for each ambulance transport. The payment for the mileage component reflects the costs attributable to the use of the ambulance vehicle — for example, maintenance, fuel, and depreciation — and is the product of miles traveled with the patient and a mileage rate determined by CMS.

Several factors adjust that per-mile rate:

• Urban vs. rural point of pickup. Where the point of pickup is in a rural area, the ground mileage rate is increased by 50 percent for each of the first 17 miles; the standard rate applies to every mile after that (42 CFR § 414.610(c)(5)(i)). The urban ground mileage rate applies to all miles of an ambulance transport originating in an urban area.
• Air ambulance rural adjustment. The amount payable for the base rate and all air miles for all air transportation originating in a rural area is 1.5 times the urban air base and mileage rates. See 42 CFR § 414.610(c)(5)(i).
• 2026 Ambulance Inflation Factor (AIF). The AIF is the change in the Consumer Price Index for All Urban Consumers (CPI-U) for the 12-month period ending in June of the prior year, reduced by a productivity adjustment required since 2011 (42 CFR § 414.610(f)), and it determines how much base rates and mileage rates increase each year. For 2026, the AIF is 2.0% — a CPI-U of 2.7% less a 0.7% productivity adjustment (CMS Transmittal 13464).
• Temporary add-on payments. The CY 2027 PFS proposed rule notes that Section 6203 of the Consolidated Appropriations Act, 2026 (Pub. L. 119-75, February 3, 2026) extended three existing add-on payments to the ambulance base and mileage rates under the Ambulance Fee Schedule for ground ambulance transports through December 31, 2027. These add-ons are: a 3% increase in the base and mileage rate for ground ambulance services originating in rural areas, a 2% increase for those originating in urban areas, and a 22.6% increase in the ground base rate (not mileage) where the pickup is in a "super rural" area — a rural area in the lowest 25th percentile by population density.
• Multiple-patient discounts. If two patients are transported simultaneously, the payment allowance for each beneficiary is 75% of the service payment allowance plus 50% of the mileage allowance; if three or more are transported, it is 60% of the service payment allowance applicable for the level of care furnished, plus the applicable mileage payment allowance divided by the number of patients on board. If you shared a transport with other patients and your bill doesn't reflect a reduced rate, that could be an error.

CMS finalized the CY 2026 Physician Fee Schedule final rule, which addresses ambulance services and revises 42 CFR § 414.610(c)(1)(ii) and 42 CFR § 414.610(c)(5)(ii) to align CMS regulations with current statutory law on the ambulance add-on payments. That matters for patients because the regulatory revision locked in the payment structure — so any bill that fails to reflect the correct add-on calculation could be systematically short- or over-charging across a large batch of claims.

What billing error patterns should I look for on my ambulance bill?

Mileage is one of the most error-prone lines on any ambulance claim. The HHS Office of Inspector General has flagged mileage overcharges repeatedly across audits. An HHS OIG report (OEI-09-12-00351) looked at claims data for 7.3 million ambulance transports furnished during the first half of 2012 and identified systematic problems with how mileage was being billed.

The OIG noted that high average mileage for transports within an urban area could indicate either billing for more miles than the ambulance supplier actually drove, or billing for mileage beyond the nearest appropriate facility. At the state level, in two claims from a 120-claim sample, a provider inaccurately documented the miles transported: one claim reported 34 miles traveled when the provider had only transported the client 13 miles, and another claim reported 247 miles when the actual distance was 24.7 miles.

Below is a decision tree to help you decide what to do first when you receive an ambulance bill with a mileage charge:

When comparing your billed miles, use the pickup address shown on the ambulance's patient care report (PCR) — which you can request — and the hospital address. Mileage is calculated from the point of patient pickup to the point of patient dropoff, not from the garage to the scene and back. A quick map check will tell you immediately if the unit count on your bill is plausible. If you are also seeing line items that seem inflated or duplicated on the broader bill, our post on phantom charges and how to dispute them explains the dispute process in detail.

Does the No Surprises Act protect me from a large ground ambulance bill?

This is where many patients get a costly surprise: the No Surprises Act provides strong protections against unexpected out-of-network bills for air ambulances and hospital-based emergency care — but ground ambulance services were deliberately left out of the law's core balance-billing ban.

The No Surprises Act took effect on January 1, 2022, as part of the Consolidated Appropriations Act of 2021. It protects patients from balance billing in three situations: emergency care, certain non-emergency care from out-of-network providers at in-network facilities, and air ambulance transport. Ground ambulance billing was left out of that list.

A Peterson-KFF Health System Tracker analysis found that about 50% of emergency ground ambulance rides and 39% of non-emergency rides resulted in an out-of-network charge for people with private health insurance. That is a significant exposure for patients who assume their insurer's in-network rate applies automatically.

The Ground Ambulance and Patient Billing (GAPB) advisory committee, which began meeting in May 2023, adopted recommendations calling for out-of-pocket ambulance charges to be capped at no more than $100 per trip, and published a report in 2024 detailing ways consumers could be protected from surprise out-of-network billing for ground ambulance services. However, it would take an act of Congress to implement any changes, so nothing has changed at the federal level for now.

As of 2026, roughly two dozen states have laws protecting consumers from surprise balance billing for ground ambulance services (published counts range from 22 to 24, depending on the tracker and the date). These state laws generally reach only state-regulated health plans, not the self-funded employer plans that cover many people with job-based insurance. If you are in a state without these protections, your best levers are: (1) confirming the mileage charge is accurate using the loaded-mile rule above, (2) filing an insurance dispute using your Explanation of Benefits (EOB) if your plan was billed for more than the allowed amount, and (3) negotiating directly with the ambulance company, which has an obligation to provide itemized billing on request. For a full breakdown of what adjustments on a hospital bill actually mean, see our guide on hospital bill adjustments and what's written off.

Illustrative example: spotting a mileage overcharge (for reference only)

The following is an illustrative example using hypothetical figures to show how a loaded-mile error appears on a bill. It is not based on any real patient's claim.

Imagine you are transported by ground ambulance from your home in a suburban ZIP code (classified as urban by CMS) to a hospital 8.2 miles away. Your itemized bill shows:

• A0429 — BLS Emergency Transport — 1 unit — $650.00 base rate
• A0425 — Ground Mileage — 23 units — $X per mile

Twenty-three units means 23 miles. But the actual loaded distance — pickup address to hospital — is 8.2 miles. The billed figure is nearly three times the actual transport distance. Where did 23 miles come from? A common cause is accidental inclusion of the unloaded return trip (hospital back to base, approximately 8 miles) plus the dispatch leg (station to your home, approximately 7 miles). Neither is billable under 42 CFR § 414.610(c)(3).

To dispute it, you would: (1) obtain your insurer's EOB to confirm what was submitted and what was allowed; (2) use mapping software to calculate the driving distance from pickup to destination; (3) write to the ambulance company's billing department citing 42 CFR § 414.610(c)(3) and requesting a corrected claim reflecting the actual 8.2 loaded miles; and (4) copy your insurer so they can coordinate the corrected payment. If upcoding of the service level (ALS billed instead of BLS) is also a concern, our post on how upcoding inflates your bill explains how to identify that separately.

About VerifyDoc: We help patients identify errors and overcharges on medical bills. We publish guides on hospital billing, the No Surprises Act, and disputing medical charges, updated as federal and state rules change.