HCPCS
A0021 — Ambulance service, outside state per mile, transport (medicaid only)
Outside state ambulance serv
Ambulance & EMS
A0429 — Ambulance service, basic life support, emergency transport
BLS emergency ambulance transport is staffed by EMTs who can provide basic care but cannot administer IV medications or perform advanced procedures.
- Typical setting: Pre-hospital emergency transport
- National avg charge (illustrative): $600–$1,800 base rate (before mileage A0425)
- Most-disputed reason: Up-coding to A0427 (ALS) when crew documentation shows only BLS-level care was provided
What it means
What A0429 actually means
BLS emergency ambulance transport is staffed by EMTs who can provide basic care but cannot administer IV medications or perform advanced procedures. This code is used for emergency calls where only basic interventions were performed.
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).
- Up-coding to A0427 (ALS) when crew documentation shows only BLS-level care was provided
- Billing emergency code A0429 instead of non-emergency A0428 for scheduled medical transport
- Failing to document medical necessity for the emergency transport
If you see A0429 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 A0429 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 A0429 on a bill.
A0429 FAQ
Plain-English answers.
What does A0429 usually cost?
$600–$1,800 base rate (before mileage 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 A0429?
Up-coding to A0427 (ALS) when crew documentation shows only BLS-level care was provided
What should I do if I see A0429 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 A0429 before paying.
Don't pay A0429 blindly.
The free scan tells you in under 60 seconds whether this charge looks reasonable for your situation.