New claim edit: Invalid patient control number
Jan 22, 2026
Stedi now rejects 837P professional, 837D dental, and 837I institutional claims that contain a patient control number (PCN) longer than 20 characters.
What is a patient control number?
A patient control number (PCN) is a tracking ID for a claim.
You create a PCN when you submit a claim. The payer sends the ID back in follow-up transactions: claim acknowledgments, Electronic Remittance Advice (ERAs), and claim status checks.
How the edit works
X12 states that PCNs can be up to 20 characters. If you submit a claim with a PCN longer than 20 characters, the payer may reject the claim, which can delay payment to the provider.
This edit – the industry term for an automated validation rule – catches the issue before the claim reaches the payer.
Rejection errors
If you submit a claim that fails the edit using Stedi’s JSON or X12 Claim Submission API endpoints, you’ll get back an error response in real time. The response includes details in the errors array:
{ "errors": [ { "code": "33", "description": "Invalid Patient Control Number. The submitted patient control number, [PCN value], exceeds the maximum allowed length of 20 characters. Correct and resubmit.", "followupAction": "Please Correct and Resubmit" } ] }
If you submit a claim that fails the edit using SFTP, Stedi will reject the claim with a 277CA claim acknowledgment. The acknowledgment will include a related claim status category code, claim status code, and error message:
STC*A7:N21*[DATE]*U*[AMOUNT]********Invalid Patient Control Number. The submitted patient control number, [PCN value], exceeds the maximum allowed length of 20 characters. Correct and resubmit
Resolution tips
Follow these best practices when creating PCNs:
Stick to 17 characters.
X12 states patient control numbers can be up to 20 characters. But some payers cut off values longer than 17 characters in ERAs and claim acknowledgments.Use a unique patient control number for each claim.
If multiple claims have the same patient control number, you may match the claim to the wrong ERA or acknowledgment.Use alphanumeric characters only.
Patient control numbers can contain both letters and numbers. Avoid special characters. Many payers don’t handle them properly.Use random strings.
Predictable formats, like {patientInitials}-{DOS}, can create duplicates.
Our recommendation: Use nanoid or a similar library to create a strong, unique 17-character patient control number for each claim.
Stedi now rejects 837P professional, 837D dental, and 837I institutional claims that contain a patient control number (PCN) longer than 20 characters.
What is a patient control number?
A patient control number (PCN) is a tracking ID for a claim.
You create a PCN when you submit a claim. The payer sends the ID back in follow-up transactions: claim acknowledgments, Electronic Remittance Advice (ERAs), and claim status checks.
How the edit works
X12 states that PCNs can be up to 20 characters. If you submit a claim with a PCN longer than 20 characters, the payer may reject the claim, which can delay payment to the provider.
This edit – the industry term for an automated validation rule – catches the issue before the claim reaches the payer.
Rejection errors
If you submit a claim that fails the edit using Stedi’s JSON or X12 Claim Submission API endpoints, you’ll get back an error response in real time. The response includes details in the errors array:
{ "errors": [ { "code": "33", "description": "Invalid Patient Control Number. The submitted patient control number, [PCN value], exceeds the maximum allowed length of 20 characters. Correct and resubmit.", "followupAction": "Please Correct and Resubmit" } ] }
If you submit a claim that fails the edit using SFTP, Stedi will reject the claim with a 277CA claim acknowledgment. The acknowledgment will include a related claim status category code, claim status code, and error message:
STC*A7:N21*[DATE]*U*[AMOUNT]********Invalid Patient Control Number. The submitted patient control number, [PCN value], exceeds the maximum allowed length of 20 characters. Correct and resubmit
Resolution tips
Follow these best practices when creating PCNs:
Stick to 17 characters.
X12 states patient control numbers can be up to 20 characters. But some payers cut off values longer than 17 characters in ERAs and claim acknowledgments.Use a unique patient control number for each claim.
If multiple claims have the same patient control number, you may match the claim to the wrong ERA or acknowledgment.Use alphanumeric characters only.
Patient control numbers can contain both letters and numbers. Avoid special characters. Many payers don’t handle them properly.Use random strings.
Predictable formats, like {patientInitials}-{DOS}, can create duplicates.
Our recommendation: Use nanoid or a similar library to create a strong, unique 17-character patient control number for each claim.
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Developers
Resources
Get updates on what’s new at Stedi
Backed by
Stedi is a registered trademark of Stedi, Inc. All names, logos, and brands of third parties listed on our site are trademarks of their respective owners (including “X12”, which is a trademark of X12 Incorporated). Stedi, Inc. and its products and services are not endorsed by, sponsored by, or affiliated with these third parties. Our use of these names, logos, and brands is for identification purposes only, and does not imply any such endorsement, sponsorship, or affiliation.
Developers
Resources
Backed by
Stedi is a registered trademark of Stedi, Inc. All names, logos, and brands of third parties listed on our site are trademarks of their respective owners (including “X12”, which is a trademark of X12 Incorporated). Stedi, Inc. and its products and services are not endorsed by, sponsored by, or affiliated with these third parties. Our use of these names, logos, and brands is for identification purposes only, and does not imply any such endorsement, sponsorship, or affiliation.
