NEMT Claim Denials in 2027: Common Reasons, Denial Codes, and Fixes

A denied claim is a ride you already gave and have not been paid for. When the cause is a missing or mismatched detail, you can fix it and resubmit while the filing window is still open. When the payer got it wrong, you can appeal. Either way, the codes on your remittance tell you where to start.

How to read a denial on your remittance

Every payment or denial comes back on a remittance advice. It can be a paper or PDF statement, or an electronic 835 file. For each claim line it shows what you billed, what was paid, and every adjustment, with codes that say why. The codes come from national lists published by X12, so a code means the same thing from every payer.

Code type	What it tells you	Example
Group code	Who the adjustment falls on	CO (contractual obligation), PR (patient responsibility), OA (other adjustment), PI (payer initiated reduction)
Claim adjustment reason code (CARC)	Why the line was paid less or denied	29: “The time limit for filing has expired.”
Remittance advice remark code (RARC)	Extra detail, often the fix	M62: “Missing/incomplete/invalid treatment authorization code.”

Read the three together. CARC 16 (“Claim/service lacks information or has submission/billing error(s)”) must come with at least one remark code, and that remark code names the field that failed. Some state programs also print their own explanation of benefits (EOB) codes next to the national ones. Look those up in your state’s provider manual or EOB code list.

See how to read remittance advice for a sample statement explained line by line, claim adjustment reason codes for more reason codes, and remittance advice remark codes for the remark codes.

Rejected, pended, or denied

• Rejected. The claim never entered processing because a required field was missing or invalid. Remark code MA130 says the claim is unprocessable, carries no appeal rights, and needs a new claim with complete, correct information. New York rejects NEMT claims that lack the ordering practitioner’s NPI.
• Pended. The claim is on hold. CARC 133 marks a line whose disposition is pending further review.
• Denied. The claim was processed and refused. You correct and replace it, or you appeal the decision. See claim rejection vs denial for how to tell which one you have.

New York’s transportation billing guidelines (version 2026-02, August 5, 2026) warn that claims that do not follow its instructions may be rejected, pended, or denied.

The checks every Medicaid claim must pass

Federal rule 42 CFR 447.45(f) requires every state Medicaid agency to review each claim before it pays. Each check lines up with a family of NEMT denials.

Federal prepayment check	How a NEMT claim fails it
The rider was in the eligibility file, and the provider was authorized to give the service, on the date of service	Coverage ended, a health plan or broker covers the trip instead, or your enrollment does not include the code
The services fit the rider’s circumstances	Too many trips or miles for one day, or a level of service the rider was not approved for
The claim does not duplicate or conflict with another	A second claim for the same trip, or base rate and mileage split across two claims
Payment stays within the state plan’s rates and limits	Units above the authorized amount or a program cap
No other insurer should pay first	Medicare or other coverage on file for the rider

The same rule requires review after payment under the fraud and utilization rules in 42 CFR parts 455 and 456. That is why a claim that paid can still come back later.

A claim that gets through without the payer needing anything more is a clean claim. The federal rule defines it as one that can be processed without obtaining additional information from the provider or from a third party. A claim from a provider under investigation for fraud or abuse, or one under review for medical necessity, does not count as clean.

The main NEMT denial reasons, their codes, and the fix

The codes below are the national codes that describe each problem. Your payer may pick a different one, so always read the remark code too.

Denial reason	Codes you may see	The fix
Rider not eligible on the date of service	CARC 26, 27, 177, 200; RARC N30	Check eligibility before the ride and again before billing. Rebill if coverage is later made retroactive.
Name or Medicaid ID does not match	CARC 31, 140; RARC N382	Copy the ID exactly from the eligibility response or the trip assignment.
Wrong payer	CARC 24, 109; RARC N904	Bill the health plan or broker that covers the rider’s trips.
No authorization, or one that does not match	CARC 197, 198, 284, 296; RARC M62, N54	Put the authorization or trip number in the right field. Match the date, code, units, and level of service to it.
Code or modifier problem	CARC 4, 181, 182; CARC 16 with RARC N822 or N823	Check the fee schedule and modifier list in force on the date of service.
Your enrollment does not cover the service	CARC 8, 170, B7; RARC N95	Confirm your enrollment, taxonomy, and service category include the code, and that the driver and vehicle were credentialed.
NPI missing or not matched	CARC 206, 207, 208; RARC N257 (billing provider) or N265 (ordering provider)	Put your billing NPI and, where required, the ordering practitioner’s NPI on the claim.
Miles or units do not fit	CARC 16 with RARC M22 or M53; CARC 151	Bill the loaded miles from the odometer or mapping record for that leg, in the units the payer uses.
Duplicate or split claim	CARC 18 (with group code OA), B13	Put each rider’s trips for one day on one claim where required. Replace a denied claim instead of resending it.
Missing trip record or attachment	CARC 252 with RARC N706 or N705; CARC 163	Send the trip report or documents the payer requires with the claim.
Filed after the deadline	CARC 29	Track every payer’s window and keep proof of when you first filed.
Service or destination not covered	CARC 96 with RARC N157; CARC 50, 117, 150	Confirm the trip went to a covered service, and the closest one that can give the care, and that the level of service matches the rider’s approval.

Two details save time. CARC 15, the old code for a missing authorization, was deactivated on May 1, 2018, so an authorization problem now arrives as 197, 198, 284, or 296. And some denied lines are expected. Indiana pays ambulatory and wheelchair van mileage only on one-way trips longer than 10 miles, and it deducts the first 10 miles itself, so bill all the miles on those trips. On a trip shorter than 10 miles, a mileage line you bill comes back denied (transportation module, version 6.1, August 19, 2025).

Eligibility denials

The rider must be covered on the date of service, not just on the day the trip was booked. A standing order can outlast the rider’s coverage.

• Check before each ride and before billing. See Medicaid eligibility verification for the tools states offer.
• Watch for coverage made retroactive. CMS’s Medicaid Transportation Coverage Guide (SMD 23-006, September 28, 2023) says states must pay claims for covered transportation a rider received during a retroactive eligibility period. In Arizona fee-for-service, a claim for a retroactive period is on time if AHCCCS receives it within 6 months of the date eligibility was posted.
• Plan for the 2027 changes. Under Public Law 119-21, for applications made on or after January 1, 2027, retroactive coverage shrinks from up to three months before the application to one month for expansion adults and two months for everyone else. Beginning with renewals scheduled on or after January 1, 2027, expansion adults must renew every 6 months instead of every 12.

States must also start work requirements for expansion adults by January 1, 2027, unless CMS grants a state an exemption, which can last no later than December 31, 2028. More frequent renewals and new work rules give coverage more chances to lapse between two rides. A check on the next day’s riders catches a lapse before the van leaves. See six-month Medicaid renewals and Medicaid work requirements and NEMT.

Authorization denials

Many NEMT trips need an approval before the ride, and the claim must carry it.

Program	What the claim needs
New York Medicaid	The 11-digit prior authorization number from the transportation roster, in Field 19 of the eMedNY claim or loop 2300 REF (qualifier G1) of the 837P. Services under different prior approvals go on separate claims.
Arizona AHCCCS fee-for-service	Prior authorization for NEMT over 100 miles for one member in a day, whether one way, round trip, or several trips. AHCCCS issues one only to a provider already registered with it.
Medi-Cal fee-for-service	An approved Treatment Authorization Request (TAR) with a legible prescription. The modifiers on the TAR and the claim must match for the claim to pay.
MTM Health, Virginia Medicaid (handbook approved August 10, 2026)	MTM’s unique trip ID, plus an electronic trip log with the scheduled and actual pickup times, departure and arrival times, and the member’s signature. A claim missing any of these, or for a trip no longer in completed status, is denied. MTM does not guarantee payment for trips run without prior authorization.

On the national CMS-1500 form, the prior authorization number goes in item 23, with no hyphens or spaces (NUCC instructions, version 13, July 2025). See prior authorization for NEMT for who issues the number and how it goes on the claim.

Match more than the number. A wheelchair trip billed under an ambulatory approval, or a date outside the approved range, fails the same way. CARC 150 reads “Payer deems the information submitted does not support this level of service.”

Code, modifier, and mileage denials

Codes and modifiers. Bill only the codes and modifiers your state or broker pays on the date of service. Arizona treats every trip that starts outside the Phoenix and Tucson metro areas as rural and requires the TN modifier. Medi-Cal allows up to four modifiers on a line, bars modifier 99 with NEMT codes, and denies any claim that puts emergency and non-emergency codes on the same form. Indiana requires a diagnosis code on every transportation claim, with R69 when the diagnosis is unknown, and denies claims without a valid one.

For the letters that show where a ride started and ended, see origin and destination modifiers. For the full code list, see NEMT billing codes.

Mileage. Medicaid pays loaded miles, the miles with the rider on board, and payers test them against the route.

• New York requires loaded miles to the tenth of a mile for dates of service on or after August 1, 2019. Rounding up is not allowed and may be treated as fraud. When one vehicle carries several riders at once, you bill the miles once, from the first pickup to the last drop-off.
• Arizona asks you to explain on the Daily Trip Report any difference between the loaded miles going and the miles coming back. Without an explanation, AHCCCS may cut the difference.
• Indiana expects the shortest, most efficient route, documented by odometer readings or mapping software.

See NEMT mileage billing for how payers measure billable miles.

Duplicate and split-billing denials

A duplicate is a second claim for a service already billed. CARC 18 reads “Exact duplicate claim/service” and is used only with group code OA. Two habits cause most of them in NEMT billing: resending a denied claim as a new claim, and splitting one day’s trips across several claims.

Arizona and Indiana both require every trip for one member on one date of service to go on a single claim. In Arizona, the base rate goes on line 1, loaded miles on line 2, and wait time, if you bill it, on line 3. Any extra lines deny. A claim with only the base code and a second claim with only the mileage are denied as split billing, and multiple claims for the same date deny as duplicates. Indiana’s one exception is a day with both brokered and non-brokered services, which go on separate claims to each payer.

A second trip on the same day can also look like a duplicate. Since its bulletin BT2025119 (August 19, 2025), Indiana has asked providers to put the XE modifier on each additional trip for a member on the same date, instead of modifier 76. Do not use XE for the legs of one trip where the driver waited for the rider, because Indiana counts that as a single trip.

Filing deadlines by payer

Federal rule 42 CFR 447.45(d) requires each state to make providers submit all claims within 12 months of the date of service. States and brokers can set shorter windows, and the ones below do.

Payer	First claim due	Fixing a denied claim
Federal outer limit (42 CFR 447.45)	Within 12 months of the date of service	Set by the state
New York Medicaid (18 NYCRR 540.6)	Within 90 days of the date of service	Within 60 days of the denial notice. A delay outside your control gets 30 days from when it ends. Every claim must be final within 2 years of the date of service.
Arizona AHCCCS fee-for-service	Within 6 months of the date of service, or of eligibility posting for a retroactive period	Reach clean claim status within 12 months of the date of service
Medi-Cal fee-for-service	Within six months after the month of service. Claims received in months 7 to 9 pay 75 percent, in months 10 to 12 pay 50 percent, and later claims deny.	A Claims Inquiry Form within six months of the remittance, or an appeal within 90 days
MTM Health, Virginia Medicaid (handbook approved August 10, 2026)	Within 6 months of the date of service, starting at the Medicare denial for trips billed to Medicare first	An appeal within 365 calendar days in MTM’s claims portal
MTM Health standard agreement (January 1, 2023 version posted by Pennsylvania)	Within 90 days of the date of service, or the limit MTM’s client sets	Through MTM’s appeals process

Keep proof of your first filing date. For a rider who also has Medicare, the federal rule lets the state pay the Medicaid claim within 6 months after the Medicare decision, as long as the Medicare claim was filed on time. When you replace a denied Arizona claim, the original claim reference number ties it to the first, timely claim. Without that number, the replacement counts as a new claim and can deny as late. Past the first deadline, New York pays a claim, and Medi-Cal pays it in full, only for an approved delay reason entered as a delay reason code on the claim.

Brokers set their own windows in each contract. How to bill NEMT brokers lists more of them, the timely filing limit page explains how to prove a claim was on time, and the timely filing calculator works out the last day for any claim.

How to fix a denied NEMT claim, step by step

1. Pull the remittance line. Write down the group code, reason code, and remark code for each denied line.
2. Match it to the trip. Open the trip record, the authorization, and the eligibility check for that date of service.
3. Choose the route.
   • Rejected or unprocessable (remark MA130): send a new, complete claim.
   • Your error, such as a wrong ID, modifier, or unit count: send a replacement claim.
   • Billed by mistake, such as a canceled ride: void the claim.
   • The payer’s error, such as a missing authorization you actually hold: appeal.
4. Build the replacement correctly. On the CMS-1500, put frequency code 7 (replacement of prior claim) or 8 (void) in item 22 with the payer’s original reference number. In Arizona, enter A or 7 with the original claim reference number, resend every line of the original claim, and attach the same documents again. Arizona recoups any paid line you leave off.
5. Know what a replacement cannot change. Arizona does not let a replacement change the service provider ID, the billing provider ID, or the tax ID. Void the claim and file a new one inside the 6-month window instead.
6. Fix the cause. A wrong modifier or rider ID on one claim may also be on that rider’s other claims. Check them, then correct the standing order or setup that caused it.
7. Log it and follow up. Track each denial by reason code and deadline until the money arrives. The claim denial log has a column for each.

For the full process, see corrected NEMT claims and how to appeal a denied Medicaid claim.

Do not send the bill to the rider. Federal rule 42 CFR 447.15 limits Medicaid to providers who accept its payment as payment in full, apart from allowed cost sharing. Arizona law bars billing AHCCCS members for covered services. MTM Health’s standard agreement bars billing members even when MTM or its client does not pay.

Denials after payment: audits and recoupments

A claim that paid can still be taken back after review. HHS Office of Inspector General (OIG) audits show what reviewers find in NEMT:

• Massachusetts (report A-01-19-00004, January 25, 2021). Of 100 sampled lines with dates of service in 2016 and 2017, drawn from rides with no medical claim billed the same day, 86 did not meet the rules. In 48, the rider received no qualifying medical service on the date of the ride. In 62, the broker could not produce enough documentation, such as the driver’s trip sheets. Two trips were billed but never given, one of them after the rider canceled.
• Indiana (report A-05-18-00043, August 25, 2020). Of 120 sampled claims, 18 did not meet the rules. For 17 of them the provider had no records at all: it had closed, left the program, moved, or could not find them.

OIG has more NEMT reviews underway. A targeted review announced October 15, 2025 (OEI-02-25-00360) uses billing red flags to find NEMT services that did not meet Medicaid rules. A new series of state NEMT payment audits was announced May 28, 2026.

When a payer recoups, you may get a window to support the claim again. In Arizona fee-for-service, you can resubmit a clean claim within the greatest of 12 months from the date of service, 12 months from eligibility posting for a retroactive period, or 60 days from the adverse action. That extra time does not apply when the AHCCCS Office of Inspector General recoups for misrepresentation. MTM Health’s standard agreement lets it recover overpayments by offsetting future payments.

See Medicaid recoupment, Medicaid audits for NEMT providers, and NEMT trip documentation requirements for how to keep paid claims paid.

How to prevent NEMT claim denials

Before the ride

• Check the rider’s eligibility and which plan or broker pays for the trip.
• Confirm the authorization or trip ID, its dates, and its level of service.
• Confirm the driver and vehicle are credentialed. MTM Health’s standard agreement pays nothing for trips by uncredentialed drivers, attendants, or vehicles.

After the ride

• Close the trip record the same day: times, loaded miles, signatures, and status.
• Compare the level of service given with the one approved.
• Put every trip for one rider and date on one claim where your payer requires it.
• Check codes, modifiers, units, and both NPIs before you submit.
• Attach the trip report the payer requires. Arizona denies any NEMT claim sent without its own Daily Trip Report.

Every week

• Submit claims well inside your shortest filing window.
• Work the denials from the latest remittance while the driver still remembers the ride.
• Count denials by reason code. The same code week after week points to a setup problem, not a one-time slip.

Brokers watch the same numbers. MTM Health’s Virginia handbook sets provider standards of under 0.29 percent of claims denied and under 0.99 percent submitted with missing or incorrect information.