An ICN (Internal Control Number) is a unique code assigned by a payer or Medicare Administrative Contractor to all claims submitted to them. Billing departments need ICNs to follow up on claim status and payment, to file a corrected claim or a void claim, or to dispute a denial. Find out how an ICN in medical billing is constructed, where it can be found, how it differs from a DCN or patient control number, and which bad habits lead to inaccurate claim documentation.
The Internal Control Number (ICN) is a unique identification number that is typically assigned by an insurance payer or Medicare Administrative Contractor (MAC) when it receives a claim. Each crucial step of the revenue cycle, including claim status checks and payment posting, is connected to the ICN.
For healthcare providers, the ICN in medical billing is a reference to the claim under consideration. This number is used to track claim status, receive payment, correct adjustments, and challenge denials.
ICNs are assigned by an insurance payer, but they are not the same as the Patient Control Number (PCN) created in-house. However, it is often used interchangeably with the Document Control Number (DCN) and Claim Control Number (CCN).
Billing professionals must understand what an ICN is and how to create, receive, and utilize the number in the revenue cycle.
- Why Does the ICN Matter for Medical Practices?
- What is the ICN Format and What Do the Digits Mean?
- Where To Find the ICN?
- How To Use the ICNs On Corrected and Void Claims?
- DCN vs. PCN vs. CCN vs. ICN in Medical Billing
- Common Mistakes When Using ICN
- Best Practices for Managing ICNs in Medical Billing
- In A Nutshell
Why Does the ICN Matter for Medical Practices?
Payers handle a high claim volume, and many claims may be similar because of the same denial reasons or services rendered. However, without ICN in medical billing, it can be challenging for billers to differentiate among claims. But that’s not all. Here are other reasons that this tracking number matters in insurance billing.
Reduced Guesswork
According to Medicare contractors, the Internal Control Number is a combination that helps identify processed claims. This number can be used by providers when they contact Medicare regarding the claim. So, in other words, it reduces ambiguity, making sure that there’s no guessing.
Claim Status Inquiries and Payer Communication
The most important information when dealing with claim denials is to decide whether the healthcare practice wishes to discuss or dispute the denial. If a staff member decides to inquire about a processed, paid, or denied claim, he will need precise information.
With the help of the ICN, the payer will immediately know which claim the provider is talking about. For instance, some Medicaid payers may allow providers to inquire about claim status by entering the ICN in a web portal or mentioning it over telephone services.
Corrected Claims and Adjustments
A payer cannot correct a claim it has already processed without knowing which claim is being referred to. This is where the Internal Control Number comes in, and also why replacement claims and voids have the same number.
Payment Differences
Sometimes payers may underpay claims due to documentation gaps, coding errors, or miscalculations, and practices must dispute them. In that case, the control number is used to assign a dedicated identifier to the disputed claim and discuss the issue for one claim rather than the account in general.
ICNs and Tracking/Receivables
Each claim has its payment history, adjustments, and follow-up notes (depending on the billing scenario). This information is recorded and assigned an ICN, which helps with revenue cycle audits.
What is the ICN Format and What Do the Digits Mean?
Firstly, no standard format applies to ICNs in medical billing. So, this tracking number can be 13 to 18 digits long. It depends on the payer, and some billing sources list varying format lengths.
So, the best way to ensure accuracy is to consider the payer’s documentation to define a format. When the format is defined, the primary elements include:
- The region or type of claims code
- Year of receipt
- Julian date (the days in the year from 001)
- Batch and sequence number
A Medicare Part B shared system (as described in one of CMS change requests) follows a 13-character pattern of RRYDDBBBSSS, which includes region, year, Julian day, batch, and sequence, as described by CMS guidance.
Medicare typically uses 14 digits on a claim, and the first five represent the Julian date of receipt (Noridian DME). We understand that this explanation might sound unclear. So, the following are examples of Medicaid and Medicare claim number structures:
Oregon Medicaid
The Oregon Medicaid adjustment handbook defines ICN in medical billing as a 13-digit number. The first two digits denote the region code, which typically indicates the source of the claim (web claim is 22, paper is 10, electronic is 20). The next two denote the year (e.g., “16” for 2016), and the next three are the day of the year (e.g., 255 for the 255th day of 2016).
After that, the next three digits are the batch number (e.g., 608), and the last three digits denote the claim sequence (e.g., 008). Therefore, the 13-digit ICN for Oregon Medicaid will be 1016255608008
Medicare
Medicare uses 14-digit Internal Control Numbers, where the last or 14th digit explains whether the claim is a first-time submission or a reworked, resubmitted, or adjusted claim. For example:
If the control number is 10261567230400:
- 10 = Paper claim with no attachments
- 26 = 2026
- 156 = 156th day of 2026
- 723 = Batch number
- 040 = Sequence number
- 0 = Original submission
Where To Find the ICN?
Understanding the exact location of this number is equally important for medical billers. Here’s what you need to know:
Remittance Advice
This tracking number is mentioned on the same line as the patient name and Medicare identification number. Some Medicaid remittance advice (such as Oregon and Missouri), like the Medicare one, includes the control number on paper. They also include the payer’s claim number on the electronic remittance advice (ERA) 835 transaction.
MAC Portals & Claim Status Tools
MAC remittance tools mention the Internal Control Number. For instance, the CGS ERA tool mentions that the ICN is sometimes called a Document Control Number (DCN), but they serve slightly different purposes (more on this ahead).
Commercial Payers Portals
Commercial payer portals may use the ICN in medical billing with different terms. For example, commercial payer portals may use Claim Number, Reference Number, or Claim Control Number to identify claims.
If a label is confusing, users can review the payer’s provider manual or contact provider services to double-check.
Practice Management and Billing Software
All billing software can store claim numbers along with the provider’s account number. The number can be imported from the 835 or from claim status. Billers just have to ensure the appropriate field for this number is part of the system to prevent it from appearing in the notes field.
How To Use the ICNs On Corrected and Void Claims?
A claim number can be used to identify modifications on a corrected claim. But if the original and corrected claim both do not have a separate Internal Control Number, the resubmitted claim may also be rejected.
Where is the ICN Added?
Billers should mention the Internal Control Number within the CMS-1500 claim form. Specifically, box 22 includes the resubmission code along with the original reference number. Conversely, for the 837P electronic claim, the first number is mentioned in the REF segment. It may also require a qualifier F8 and the frequency code in CLM05-3 (depending on the scenario).
Frequency Codes
Frequency code 7 denotes a replacement of the previous claim, and frequency code 8 voids or cancels it. Remember, a replacement claim replaces the whole claim, not just the modifications. So, all charges should be mentioned appropriately.
Payer-Specific Rules
The payer-specific rules for ICN may vary. So, billers should review the payer’s manual before billing. For instance, Michigan’s control number contains 14 digits, but there may be a “710” plan code.
The code is included at the end in web-DENIS and 835. Thus, the number will contain 17 digits. Michigan also requires a control number of the last adjusted claim when a claim has already been adjusted.
DCN vs. PCN vs. CCN vs. ICN in Medical Billing
The following table covers the differences between different identifiers used in medical billing:
| Identifier | Full Form | Assigned By | Where to Find It | Primary Purpose |
|---|---|---|---|---|
| ICN | Internal Control Number | Payer or MAC | Remittance advice, payer portals, and REF*F8 on corrected claims. | Identifying, tracking, and referencing a processed claim. |
| DCN | Document Control Number | Payer | Remittance advice, Electronic Remittance Advice (ERA), and payer portals. | Similar to the Internal Control Number; used by payers that adopt this terminology. |
| CCN | Claim Control Number | Some Medicare contractors | Remittance advice. | Serves the same purpose as the Internal Control Number. |
| PCN | Patient Control Number | Healthcare provider | Box 26 of the CMS-1500 claim form and returned remittance advice. | Tracking payments and associating claims with the correct patient account internally. |
Is the ICN Equivalent to the Claim Number?
Generally, yes. The internal number is typically equivalent to the payer-assigned claim number since it identifies and tracks claims after the payer is done processing. But terminology can vary among payers.
Common Mistakes When Using ICN
This number results in various billing errors that professionals should avoid. Here’s a quick breakdown of the common errors.
Confusing ICN and PCN
The PCN belongs to you, and the insurance company won’t use it to search the same way it uses its own number.
Reporting Incorrect or Expired Identifier
If you give the insurance representative an incorrect or obsolete number, they will find the wrong claim.
Missing Updated Identifiers
Each time a claim is adjusted or corrected, a new control number may be assigned to it. Overlooking this new identifier can lead to filing errors.
Neglecting Reconciliation
Billers that neglect reconciliation of submitted or corrected claims often find overlapping numbers of different claims.
Skipping Information Verification
Billers should always verify the date of service, patient, charges, and the status of the payer before making any changes.
Best Practices for Managing ICNs in Medical Billing
Although identifier management seems simple at first, being reckless with it can cause mistakes. Here are some practices billers should adopt to manage these numbers in medical billing.
1. Store the Payer-Assigned ICN
Save control numbers along with your own numbers. Keep the control number with the patient account number and claim number in a special field.
2. Use a Centralized Claim Tracking System
Vital information such as the initial claim and subsequent adjustments, replacements, and voids should be recorded in the same system.
3. Add Specific Details to the ICN
Crucial details related to the claim submission (which may include service date, payer, and current status) should be added to the number.
4. Make Reconciliations Regularly
Compare identifiers on ERAs, remittance advice, and the payer portal with your data on a specific schedule.
5. Standardize the Follow-up Process
A scattered billing system can cause trouble in the follow-up process. Therefore, the information should be processed and managed carefully. Most new practices lack this skill, but providers of outsourced medical billing services can handle it for you.
In A Nutshell
ICN lets billing teams track claims and determine reasons for claim denial. It aids payment posting and claim correction, ultimately streamlining the revenue cycle.
We understand managing so many control numbers can be challenging, along with patient care. Fortunately, MediBillMD can help you handle this task efficiently.
