ICN Number in Medicaid: What the Claim Number on Your Remittance Tells You

What an ICN is

When a claim reaches a state Medicaid claims system, the system stamps it with its own tracking number. Many states call that number the internal control number, or ICN. It is the payer’s number for the claim, separate from the patient account number you put on the claim yourself.

You meet it in three places:

• The remittance advice. Indiana’s remittance prints it in a field labeled ICN. Its provider portal shows the same number as the Claim ID.
• The 835 file. Each claim’s CLP segment carries it in CLP07. Indiana’s remittance guide maps its ICN field there, and South Dakota’s 835 guide describes CLP07 as the claim reference number the state assigns. See 835 ERA for the rest of the file.
• The payer’s portal and phone lines, where it is the fastest way to find one claim.

Not every state uses the term. Texas prints its ICN as the claim number on the weekly Remittance and Status (R&S) report, and other states use names such as transaction control number or claim reference number. Our guide to checking Medicaid claim status lists what several states call it.

How to read an Indiana ICN

Indiana Medicaid gives each claim a unique 13-digit number in the pattern RR YY JJJ SSSSSS (Claim Submission and Processing module, version 8.5, February 24, 2026):

• RR, digits 1 and 2: the region code, which shows how the claim arrived or what kind of adjustment it is.
• YY, digits 3 and 4: the year the claim was received.
• JJJ, digits 5 to 7: the Julian day it was received, counted from January 1.
• SSSSSS, digits 8 to 13: a batch number, then the claim’s place in the batch. The first claim in a batch ends in 000. Paper batches hold up to 100 claims, electronic batches up to 1,000.

Paper claims and their attachments share one ICN, given when they are scanned.

Region codes a transportation company sees

The region code is the quickest read on a remittance. These are the codes most likely on a transportation company’s claims:

Code	What it means
10	Paper claim, no attachments
11	Paper claim with attachments
20	837 electronic claim, no attachments
21	837 electronic claim with attachments
22	Portal claim, no attachments
23	Portal claim with attachments
50	Paper single replacement, not tied to a refund check
51	Replacement tied to a refund check
52	Mass replacement, not tied to a refund check
56	Mass void, or a single void on paper or after an audit
61	Your electronic replacement with an attachment or claim note
62	Your electronic replacement, no attachment or note
63	Your electronic void
80	Denied claims reprocessed

Codes 52 and 80 mean the state’s Medicaid office, its rate contractor, or Gainwell reprocessed a group of claims, which it does after a system problem or a retroactive rate or policy change. Read the new payment line before you rebill anything.

An Indiana example

In Indiana, trips brokered through Verida are paid by Verida under its own contract. Some trips are billed straight to Gainwell, Indiana Medicaid’s claims processor, and those get an ICN. Hospital-to-hospital transports are one example: they are never brokered, and the base rate and mileage both carry the HH modifier (Transportation Services module, version 6.1, August 19, 2025).

Say your company sends that claim through your billing system on October 6, 2026, and the remittance shows ICN 2026279045012. Read it left to right:

1. 20. It came as an 837 electronic claim with no attachments.
2. 26. It was received in 2026.
3. 279. Day 279 of 2026 is October 6.
4. 045 and 012. Batch sequence 045, and the 13th claim in that batch.

The base rate paid, but the mileage line denied because the HH modifier was left off it. Indiana requires base rate and mileage on the same claim, so you cannot send the mileage as a new claim. You submit an adjustment instead (Claim Adjustments module, version 8.0, January 29, 2026). In the portal, you open the paid claim and edit it, and the confirmation shows the replacement’s own Claim ID. If you send it on October 12, it starts 6226285: a provider electronic replacement, received on day 285 of 2026.

On the next remittance, the adjustment shows two header lines, the original claim and then the replacement. From then on, quote the replacement’s ICN. Indiana adjusts only the most recent paid claim, and its corrected replacement must arrive within 60 days of the remittance date that paid the original. Our guide to corrected NEMT claims covers the deadlines in other states.

How to read a Texas ICN

TMHP, the claims administrator for Texas Medicaid, prints a 24-digit ICN as the claim number on the R&S report (Texas Medicaid Provider Procedures Manual, claims filing section, October 2026). It breaks into PPP/CCC/MMM/CCYY/JJJ/BBBBB/SSS:

• PPP: the program. 100 is Medicaid.
• CCC: the claim type.
• MMM: the media source, or how the claim came in. 010 is paper and 030 is electronic, including TexMedConnect. Adjustments carry their own codes, such as 011 for a paper adjustment and 031 for an electronic one.
• CCYY and JJJ: the four-digit year and the Julian day received.
• BBBBB and SSS: TMHP’s internal batch number and the claim’s place in it.

So the 7th to 9th digits tell a paper claim from an electronic one at a glance.

Texas shows an adjustment as two claims. The adjusted claim prints first, followed by explanation code 00123, which names the previous claim’s 24-digit number and the date of the R&S report it appeared on. The original claim prints below it. Code 00601 then says a receivable has been set up for the full original payment, and future payments are reduced or withheld until it is repaid. Track that receivable until it clears.

Companies in the Medical Transportation Program get this R&S report each week they have claim or financial activity, as a PDF, on paper, or as an 835 file (Medical Transportation Program Handbook, October 2026).

When you need the ICN

Keep the ICN with each trip in your billing records. You will need it for:

• A replacement or void. On a paper CMS-1500, item 22 takes the frequency code, 7 to replace or 8 to void, with the payer’s number in the Original Ref. No. area, which holds up to 18 characters (NUCC instructions, version 13.0, July 2025). The 837P has its own field for it, and the steps are in our guide to corrected NEMT claims.
• An appeal. Texas must receive an appeal or adjustment request within 120 days of the R&S report on which the claim appears. A paper appeal includes a copy of that R&S page with one claim circled per page.
• A status check or a call. Quote the ICN first when you call or search a payer’s portal.
• Posting the payment. Match the ICN to your own account number on the same claim line, then to the trip. Our walk-through on reading a remittance advice shows each field.