HCPCS
A0021 — Ambulance service, outside state per mile, transport (medicaid only)
Outside state ambulance serv
Ambulance & EMS
A0427 — Ambulance service, advanced life support, emergency transport, level 1
This is the billing code for an ALS-level emergency ambulance ride — the kind staffed by paramedics who can start IVs, give medications, and perform advanced procedures.
- Typical setting: Pre-hospital emergency transport
- National avg charge (illustrative): $800–$2,500 base rate (before mileage, which is billed separately as A0425)
- Most-disputed reason: Billing A0427 (ALS-1) when the patient received only basic life support (should be A0429) — up-coding level of service is a common fraud pattern
What it means
What A0427 actually means
This is the billing code for an ALS-level emergency ambulance ride — the kind staffed by paramedics who can start IVs, give medications, and perform advanced procedures. It is billed when at least one ALS intervention was performed or the patient's condition required ALS-level care.
Common errors with this code
What goes wrong on real bills.
Most bills that look correct still contain at least one of these issues. Up to 49% of medical bills contain errors (CFPB).
- Billing A0427 (ALS-1) when the patient received only basic life support (should be A0429) — up-coding level of service is a common fraud pattern
- Double-billing both A0427 and A0429 for the same transport
- Not itemizing mileage separately (A0425 per mile); mileage is always a separate line item
If you see A0427 on your bill
Three steps before paying.
1. Get the itemized bill. If your statement only shows a summary, request the CPT-level itemized bill before paying. Generate the request language →
2. Cross-check against the EOB. Compare what your insurer's Explanation of Benefits says you owe versus what the hospital is asking. They disagree more often than people think. Read the bill-vs-EOB guide →
3. Run a free Bill Scan. Upload the bill (and EOB if you have it) and BillBusted will flag the most likely issues with this specific code in your specific state. Run free scan →
Related codes
Other codes in this category.
People who land on A0427 often also see these adjacent codes on the same bill.
HCPCS
A0080 — Non-emergency transportation, per mile - vehicle provided by volunteer (individual or organization), with no vested interest
Noninterest escort in non er
HCPCS
A0110 — Non-emergency transportation and bus, intra or inter state carrier
Nonemergency transport bus
HCPCS
A0120 — Non-emergency transportation: mini-bus, mountain area transports, or other transportation systems
Noner transport mini-bus
Related BillBusted guides
Plain-English reads if you see A0427 on a bill.
A0427 FAQ
Plain-English answers.
What does A0427 usually cost?
$800–$2,500 base rate (before mileage, which is billed separately as A0425). Costs vary by region, payer contract, and whether the service was performed in a hospital outpatient department (which adds a facility fee) versus a free-standing clinic.
What's the most common billing error on A0427?
Billing A0427 (ALS-1) when the patient received only basic life support (should be A0429) — up-coding level of service is a common fraud pattern
What should I do if I see A0427 on my bill?
Request the itemized bill and the matching EOB from your insurer. Compare the units/quantity billed against what you actually received. Run a free BillBusted scan to flag the most likely errors specific to A0427 before paying.
Don't pay A0427 blindly.
The free scan tells you in under 60 seconds whether this charge looks reasonable for your situation.