# What Is an 837P Claim? How a NEMT Trip Is Laid Out in the Electronic Claim

Canonical URL: https://nemtguide.com/glossary/837p/ · Updated 2026-09-30

The 837P is the HIPAA standard electronic format for professional claims, the file version of the paper CMS-1500. A NEMT company sends one to bill Medicaid or a health plan electronically. It holds the same data in named loops: your company in loop 2010AA, the rider in 2010BA, the claim and its authorization in 2300, and each code, date, and mileage unit in 2400.

- The 837P is version 5010 of the X12 professional claim, and payers expect 005010X222A1 in the file header.
- Every CMS-1500 box has a home in the file, from box 1a (loop 2010BA) to box 33a (loop 2010AA).
- Trip details go where your payer says: New York wants the authorization in loop 2300, Arizona wants both addresses in the claim note.
- Claim frequency code 1 sends a new claim, 7 replaces a paid one, and 8 voids it.
- If you bill electronically, federal rules require the standard format, but a payer portal may take the same data by typing.

## What an 837P is

The 837P is the electronic professional claim, the one NEMT companies use. The "837" is the X12 claim transaction and the "P" means professional, as opposed to institutional (837I, for hospitals) or dental (837D). Federal rules adopt it as the HIPAA standard for professional claims, version 5010, named ASC X12N/005010X222 ([45 CFR 162.1102](https://www.ecfr.gov/current/title-45/section-162.1102)). Changes already scheduled for August 14, 2027 and April 14, 2028 update the pharmacy standard and keep the 837P at version 5010.

The rule that makes it matter is simple. If you send a claim electronically to a health plan, you must send it as the standard transaction ([45 CFR 162.923](https://www.ecfr.gov/current/title-45/section-162.923)). State Medicaid programs are health plans under HIPAA ([45 CFR 160.103](https://www.ecfr.gov/current/title-45/section-160.103)). Typing a claim into a payer's web portal is the main exception: you skip the file format, but you still enter the data the standard requires.

So you have three ways to bill: the paper [CMS-1500](https://nemtguide.com/guides/cms-1500-for-nemt/), the payer's portal, or an 837P file. The file can come from your own billing software or from a [clearinghouse](https://nemtguide.com/glossary/clearinghouse/). How to sign up for each route is in [how to submit NEMT claims electronically](https://nemtguide.com/guides/submit-nemt-claims-electronically/).

## How an 837P file is organized

An 837P is a text file made of segments, each one a short line of data elements. The segments nest inside an envelope and a set of numbered loops, from the sender down to each service line. Payers describe their rules by loop and element, so knowing the layout lets you read any companion guide.

| Part | What it holds for a NEMT claim |
|---|---|
| ISA and GS (envelope) | Who sent the file and who receives it. GS08 names the version, which Arizona and Nevada expect as 005010X222A1. Arizona requires every file's control number in ISA13 to be unique. |
| Loop 1000A and 1000B | The submitter (you or your clearinghouse) and the receiver (the payer) |
| Loop 2000A and 2010AA | The billing provider: your company's name, street address, NPI, and tax ID. Your taxonomy code goes in the 2000A PRV segment. |
| Loop 2000B, 2010BA, 2010BB | The subscriber, which for Medicaid is usually the rider, with the Medicaid ID. Then the payer. |
| Loop 2300 | The claim: your account number, total charge, place of service, claim frequency code, diagnosis, prior authorization number, and claim notes |
| Loops 2310A to 2310F | Other parties at the claim level: referring provider, rendering provider, service facility, supervising provider, and ambulance pickup and drop-off locations |
| Loop 2400 | One loop per service line: the procedure code and modifiers, the charge, the units, and the service date |

Arizona adds details for its own files. The subscriber level must show no separate patient below it, so the rider is the subscriber. The billing address must be a physical address, never a P.O. box or lock box (AHCCCS 837 companion guide, version 4.0, November 2022).

## Where each CMS-1500 box goes in the 837P

The NUCC publishes the official crosswalk, its 1500 Claim Form Map to the 837P (version 3.3, August 2018). These are the boxes a NEMT claim uses most.

| CMS-1500 box | What it holds | 837P loop and element |
|---|---|---|
| 1a | Rider's Medicaid or plan ID | 2010BA NM109 |
| 2 and 3 | Rider's name, birth date, and sex | 2010BA (or 2010CA) NM1 and DMG |
| 17 and 17b | Referring or ordering provider and NPI | 2310A, 2310D, or 2420E NM1 and NM109 |
| 19 | Additional claim information | 2300 NTE or PWK, or a REF in a 2310 loop |
| 21 | Diagnosis codes | 2300 HI |
| 22 | Resubmission code and original claim number | 2300 CLM05-3 and REF02 |
| 23 | Prior authorization number | 2300 REF02 |
| 24A | Date of service | 2400 DTP03 |
| 24B | Place of service | 2300 CLM05-1, or 2400 SV105 for one line |
| 24D | Procedure code and modifiers | 2400 SV101 |
| 24E | Diagnosis pointer | 2400 SV107, as numbers, not letters |
| 24F and 24G | Charge and units | 2400 SV102 and SV104 |
| 24I and 24J | Rendering provider qualifier and ID | 2310B or 2420A PRV, REF, and NM109 |
| 25 | Federal tax ID | 2010AA REF |
| 26 and 28 | Your account number and total charge | 2300 CLM01 and CLM02 |
| 32 and 32a | Service facility and its NPI | 2310C NM1 and NM109 |
| 33 and 33a | Billing provider and NPI | 2010AA NM1, N3, N4, and NM109 |
| 33b | Other ID or taxonomy | 2000A PRV03, or a 2010AA REF |

A few paper boxes have no 837P home. Box 8 (once Patient Status), box 9b, box 9c, and box 30 (once Balance Due) do not exist in the electronic claim. For who belongs in box 33 versus box 24J, see [billing provider vs rendering provider](https://nemtguide.com/glossary/billing-vs-rendering-provider/).

## One NEMT trip inside an 837P

Here is where the facts of one ride land, using the map above. Picture a wheelchair van ride from a member's home to a doctor's office, billed with A0130 for the trip and S0209 for the loaded miles. Your own codes and units come from your state fee schedule; see [NEMT billing codes](https://nemtguide.com/guides/nemt-billing-codes/).

| Fact about the ride | Where it goes |
|---|---|
| The rider's Medicaid ID | 2010BA NM109 |
| Your internal trip or invoice number | 2300 CLM01, which comes back on your remittance |
| Total charge for the claim | 2300 CLM02 |
| New claim, replacement, or void | 2300 CLM05-3 |
| The authorization number from the trip order | 2300 REF, with the qualifier your payer names |
| A diagnosis code | 2300 HI |
| Line 1: [A0130](https://nemtguide.com/glossary/a0130/) with the RP modifier (residence to physician's office) | 2400 SV101, with 1 unit in SV104 |
| Line 2: S0209 for the loaded miles | 2400 SV101, with the miles as units in SV104 |
| Date of the ride | 2400 DTP03, on each line |

The two letters after the code are [origin and destination modifiers](https://nemtguide.com/glossary/origin-destination-modifiers/): the first letter is where the ride started and the second where it ended.

## What NEMT payers ask for inside the 837P

The standard leaves room for each payer to say which optional pieces it needs. For transportation, that is usually the authorization, the addresses, and sometimes the times. These rules show the range as of September 2026.

| Payer | What it asks for in the 837P |
|---|---|
| New York Medicaid (billing guidelines, version 2026-02, August 5, 2026) | The 11-digit prior authorization number from the transportation roster in 2300 REF02, with REF01 = G1, one authorization per claim. Place of service 99 for non-emergency trips in CLM05-1. A diagnosis is required on electronic claims, and R69 may be used when nothing more specific is known. Miles or number of round trips in 2400 SV104. For ambulette and taxi or livery claims, the vehicle's license plate in loop 2310B and the driver's nine-character license number in loop 2310A. |
| Arizona AHCCCS fee-for-service (Chapter 14, revised July 31, 2026, and companion guide 4.0) | Since November 1, 2022, full pickup and drop-off addresses on every NEMT claim, in the 2300 NTE claim note, written like "P-123 Main St Phoenix AZ 85051 D-456 Uptown St Phoenix AZ 83034". Providers without an NPI send G2 and their AHCCCS ID, with two leading zeros and a location code, in a 2010BB REF. |
| Indiana Medicaid (companion guide 4.2, November 2024) | Atypical billing providers, which include most transportation providers, send their IHCP Provider ID in a 2010BB REF with G2. Claim frequency codes 1, 7, and 8. Required attachments go by mail only. |
| Nevada Medicaid, NEMT encounter files (companion guide updated August 4, 2026, for its modernized claims system) | Origin and destination modifiers on every procedure code, or U1 and U2 on pharmacy trips. For A0080, A0120, A0130, and T2005, the appointment time, scheduled pickup, actual pickup, and actual drop-off in the 2400 NTE line note, written like "AT1400,PT1230,PA0000,AD1330". |

Nevada's guide covers encounter files, which report rides to the state, rather than claims a ride company sends to be paid. It still shows how trip times can travel inside the standard.

Qualifiers are one place the paper form and the file differ. In the file, an NPI carries the qualifier XX and a taxonomy code in the PRV segment carries PXC, as the samples in Indiana's companion guide show. On the paper form's box 33b, the taxonomy qualifier is ZZ instead (NUCC instruction manual, July 2025).

## Fixing a sent 837P claim

You do not fix an electronic claim by sending it again as new. You send the same claim with a frequency code in CLM05-3 that tells the payer what to do.

| CLM05-3 | Meaning | What else to send |
|---|---|---|
| 1 | Original claim | Nothing extra |
| 7 | Replacement of a claim already processed | The payer's claim number for the original, in a 2300 REF. Arizona calls it the Claim Reference Number (CRN). |
| 8 | Void of a claim already processed | The same original claim number |

Nevada allows adjustments only on encounters it has already accepted and paid, and wants the most recent claim number used. Before you replace a claim, check what your payer allows, and see [corrected NEMT claims](https://nemtguide.com/guides/corrected-nemt-claims/).

## How to read an 837P rejection

A file can fail at three levels. The envelope can fail (a TA1 report), the file can fail its format check (a 999), or one claim can fail the payer's own edits after that. Indiana, for example, returns claims that fail its billing provider check on a 277U claim status report, not on the remittance advice. Nevada says its 999 is normally ready one hour after you send a file, and can take up to 24 hours. Nevada rejects a whole transaction set for one compliance error in it, so you fix the bad claim and send the entire set again. Read each report the day it arrives. See [how to check Medicaid claim status](https://nemtguide.com/guides/check-medicaid-claim-status/) for what to do next.

## Frequently asked questions

### Is the 837P the same as the CMS-1500?

They carry the same claim, in two formats. The CMS-1500 is the paper form, and the 837P is the electronic transaction. The NUCC, which maintains the paper form, publishes a map that links each numbered box to a loop and data element in the 837P. A few paper boxes have no electronic match, such as box 30, which was once Balance Due.

### Do I need a clearinghouse to send an 837P?

No. You can send 837P files from your own billing software if you sign up with the payer as a trading partner and pass its testing, or a clearinghouse can build and send them for you. Many Medicaid programs also let you type claims into a web portal, which HIPAA allows as long as you enter the data the standard requires (45 CFR 162.923(b)).

### What diagnosis code goes on a NEMT 837P?

The one your payer names. Diagnosis codes go in loop 2300, and some payers require one even for rides. New York makes it a required field on electronic transportation claims and says R69 may be used when a more specific diagnosis is not available (billing guidelines, August 5, 2026). Nevada's companion guide for NEMT encounter files requires Z76.89. Check your state manual or your payer's companion guide.

### What does 005010X222A1 mean?

It names the version of the professional claim you are sending: X12 version 5010 of the professional claim guide (X222), with its June 2010 corrections, called Type 1 Errata (A1). Arizona and Nevada both expect it in the GS08 and ST03 elements at the top of the file. Your billing software or clearinghouse fills it in, but it is the first thing to check when a whole file comes back.

### Can I send an 837P to a NEMT broker?

Only if the broker takes files. Many brokers take claims in their own online system instead. MTM Health's standard agreement, in the January 1, 2023 version Pennsylvania posts, pays properly submitted, uncontested invoices within 30 days after online electronic submission. Health plans are different: a HIPAA health plan must accept a standard 837P if you ask to send one (45 CFR 162.925).

## Official resources

- [NUCC: 1500 Claim Form Map to the X12 837P (every box, loop by loop)](https://www.nucc.org/images/stories/PDF/1500_claim_form_map_to_837P_v3-3_2012_02.pdf)
- [NUCC: 1500 Claim Form Reference Instruction Manual](https://www.nucc.org/images/stories/PDF/1500_claim_form_instruction_manual_2025_07-v13.pdf)
- [eMedNY: Transportation Billing Guidelines (837P reference for every field)](https://www.emedny.org/ProviderManuals/Transportation/PDFS/Transportation_Billing_Guidelines.pdf)
- [AHCCCS: 837 Standard Companion Guide](https://www.azahcccs.gov/Resources/Downloads/EDIchanges/AZ837CLAIMS.pdf)
- [Indiana Medicaid: 837P Companion Guide](https://www.in.gov/medicaid/providers/files/837p-health-care-claim-professional-transaction.pdf)