Fixing a paid or denied NEMT claim: replacement and void claims explained

The claim’s status picks the fix

What you send depends on how far the claim got with the payer, and the remittance shows that.

• Rejected. The claim failed intake and was never decided, so nothing exists to replace. Fix the data and send an original. Texas accepts a corrected electronic claim after a 277CA rejection as long as the 95-day filing limit from the trip date is still open. MediTrans keeps rejected Louisiana claims in rejected status for the rest of the 365-day filing window, and they never show on a remittance.
• Denied. Most programs want a new claim once the error is fixed. Colorado says to rebill a denied claim electronically as a newly created claim, which receives a new internal control number (ICN). Ohio counts a resubmitted denied claim as timely when it arrives inside 365 days from the trip date.
• Paid, but wrong. Send a replacement, frequency code 7, that restates the whole claim correctly. Colorado calls this an adjustment and denies corrections to paid claims that come in as rebills.
• Paid, but never billable. Send a void, frequency code 8, and the payment is recovered. Nevada’s companion guide labels it a credit-only void.
• In process or suspended. Leave it alone. Colorado warns against rebilling or adjusting in-process claims, since each one finishes as paid or denied on a later remittance.
• Billed to a broker. Work through the broker’s portal and rules under its trip ID. MTM Health in Virginia takes corrected information through appeals in its claims portal for 365 calendar days after a denial, and wants a claim billed by mistake reported to your Field Monitor immediately so MTM can void it. WellTrans accepts a claim denied for missing information once the gaps are filled.

A correction is for your own mistakes. When the claim was right and the payer ruled wrongly, the route is a reconsideration or appeal, covered in appealing a denied NEMT claim.

Where the frequency code and claim number go

Paper and electronic claims mark a correction in matching places:

The NUCC instruction manual (version 13.0, July 2025) sets the paper rules and tells billers to follow each payer’s current instructions for the box. Colorado’s NEMT billing manual lists codes 7 and 8 for box 22. Nevada’s fee-for-service 837P companion guide (updated July 6, 2026) wants its 13-digit ICN in the F8 reference. Our guides to the CMS-1500 for NEMT and the 837P for NEMT cover the rest of each form.

Cite the newest claim number

Every processed claim carries a payer-assigned number, and each adjustment creates a new one. Nevada requires the most recently paid ICN when adjusting or voiding. Colorado gives a resubmitted adjustment a new ICN. Copy the number from the latest remittance or from the payer’s portal. Your own invoice number means nothing to the payer.

A Colorado ICN is 13 digits, and its first two digits, the region code, show how the claim or adjustment came in:

After the 365-day filing window, Colorado also wants the previous ICN on every resubmission. On a paper CMS-1500, that means the previous ICN in box 22 with resubmission code 9F.

What happens to the original payment

A replacement is not an add-on to the first payment. The payer reprocesses the whole claim, recovers what it paid the first time, and pays the new total.

Texas prints the sequence on its R&S Report. The adjusted claim appears first, followed by explanation code 00123 identifying the earlier claim, and then the claim as it was originally processed. TMHP sets up an account receivable for the original payment (explanation code 00601), and future payments are reduced or withheld until it is repaid.

Colorado shows adjustments in their own section of the remittance, next to the original claim. When the adjusted claim pays less than the original, or nothing, the system creates an account receivable for the balance.

The practical rule follows from those mechanics. Since the first payment is taken back in full, a replacement that lists only the changed line leaves the payer holding a smaller claim than the one it paid. Restate every line, including the ones that were right.

Correction deadlines

Correction windows are separate from first filing limits, and many run from the remittance date. First filing limits are covered in timely filing limits.

Colorado’s 60-day rule keeps older claims alive. Once 365 days have passed, each rebill or adjustment has to reach the fiscal agent within 60 days of the previous action, carrying the previous ICN, even when the claim keeps denying. Miss one of those windows and the claim falls out of timely filing. Ohio takes claim adjustments only through electronic submission or its provider web portal.

Texas also limits what a correction can change, and how:

• By phone. The Automated Inquiry System accepts corrections to the patient control number, place of service, quantity billed, prior authorization number, and dates of service that stay within the filing deadline.
• Not electronically. Electronic appeals cannot change the quantity billed, so a corrected mileage count goes through the phone system or on paper.
• Zero-paid claims. A zero-paid electronic claim can be resent as a new claim after the 95-day deadline only when the NPIs, the client’s Medicaid number, the dates of service, and the total billed amount are unchanged. Any change to those fields needs a paper appeal with a copy of the R&S Report.

Whatever the route, correct only toward what the trip log proves. A replacement that adds miles or a return leg needs that record behind it, or it turns into an audit finding. NEMT documentation requirements lists what the record should hold.

Keeping corrections from denying as duplicates

Before paying, every state must check that a claim does not duplicate or conflict with one already reviewed or under review (42 CFR 447.45). On the remittance, the X12 reason code for an exact duplicate is 18, which X12 reserves for use with group code OA.

Texas defines the match: a claim or line identical to one already paid to the same provider for the same client, with the same date of service, procedure code, modifier, and number of units. It adds that modifiers can mark services that are truly separate, which is why each leg needs the right origin and destination modifiers.

Indiana prevents duplicates through claim structure. All transportation for one member on one date goes on a single claim. A same-day round trip at the same level goes on one detail line with two units, and its mileage goes on one line. Since bulletin BT2025119 (August 19, 2025), each additional, separate trip on the same date carries modifier XE on its detail line to show it is separately payable. XE does not apply when the driver waited for the rider between stops, because Indiana treats that as one trip.

Habits that keep duplicate flags off the remittance:

• Give a claim 30 days to appear before resending it. Texas asks providers to resubmit only when a claim is still missing from the weekly R&S Report after 30 days, and only while the 95-day limit is open.
• Mark every correction. Without the frequency code and the payer’s claim number, a corrected claim looks like a second bill for the same trip.
• Add a forgotten leg to the existing claim for that date through a replacement, where the payer wants one claim per rider per day, as Indiana does.
• Expect brokers to net duplicates out. WellTrans can offset duplicate payments against future payments.

Returning money you should not have received

An overpayment is money paid for a trip that should not have been billed, or paid twice. Under 42 U.S.C. 1320a-7k(d), the provider must return it and explain the reason in writing by the later of two dates: 60 days after identifying it, or the due date of any related cost report. Money held past that point becomes an obligation under the False Claims Act.

Each payer sets the mechanics:

• Ohio expects an electronic adjustment within 60 days of finding the overpayment, and accepts refund checks only in listed situations, such as an overpayment invoice, a collection letter, or an audit.
• Colorado wants overpayments reported immediately. It subtracts the amount from current claim payments or holds it as a balance against future ones, and it also takes a check for the full incorrect payment sent with its refund form.
• Texas takes repayment by check, mailed with its Refund Information Form and a copy of the R&S Report page, or through a recoupment requested by paper appeal, which takes the amount off a later report instead.
• Brokers usually offset. MTM Health and WellTrans agreements let them recover overpayments from future payments. MediTrans gives providers 30 days to contest an overpayment notice, or 60 days when it follows a special investigations finding.

The 60-day overpayment rule covers the reporting duty in more depth, and Medicaid recoupment covers money taken back after an audit.

Fewer corrections from better trip records

A correction is cheapest when it never has to happen. HealthRide stores each leg’s level of service, planned and actual times, signatures, and GPS-recorded miles together, and the trip log exports it for any date range. For facilities and private-pay riders, unpaid invoices can take added fees or discounts, and a voided invoice stops its payment link while the books stay accurate.