New claim edit: Invalid drug unit count
Dec 10, 2025
Stedi now rejects 837P professional and 837I institutional claims that bill for a drug or biologic without a valid unit count.
In professional and institutional claims, you bill for drugs or biologics by adding information about the drug to a service line, specifying what drug was administered and how much.
The line’s unit of measurement code – such as F2 (International Unit) or GR (Gram) – shows how the drug was measured. The line’s unit count reports the quantity administered in that measure.
Payers use the measurement code and unit count to verify dosage and pricing. Without a valid unit count, they can’t confirm the billed amount and may reject the claim, which can delay payment.
This edit – the industry’s term for an automated validation rule – catches the issue before it reaches the payer.
When this edit applies
A professional or institutional claim will fail this edit in the following cases:
JSON API
If you’re using one of Stedi’s JSON claim submission API endpoints, the edit fails if:A service line contains a
drugIdentification.measurementUnitCodevalue.
ANDThe service line’s
drugIdentification.nationalDrugUnitCountfield is less than or equal to”0”.
Raw X12
If you’re using raw X12, the edit fails if:Loop 2410(Drug Identification) is present
ANDThe
CTP-05(Composite Unit of Measure) ofLoop 2410contains a value.
ANDThe
CTP-04(National Drug Unit Count) ofLoop 2410is less than or equal to0.
Stedi portal
If you’re using the Stedi portal’s professional claim form, the edit fails if:Box 24 – Service Lines contains a service line with a Unit/Basis of measurement value and a Quantity less than or equal to zero.

Rejection errors
If you submit a claim that fails the edit using Stedi’s claim submission APIs or professional claim form, you’ll get back an error message in real time. If you’re using a JSON API endpoint, the response includes error details in the errors array:
{ "errors": [ { "code": "33", "description": "Invalid drug unit count. When reporting a drug unit qualifier, the drug count must be greater than zero (0.0). 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 contain a related claim status category code, claim status code, and error message. You can use the error message to correct and resubmit the claim.
Stedi now rejects 837P professional and 837I institutional claims that bill for a drug or biologic without a valid unit count.
In professional and institutional claims, you bill for drugs or biologics by adding information about the drug to a service line, specifying what drug was administered and how much.
The line’s unit of measurement code – such as F2 (International Unit) or GR (Gram) – shows how the drug was measured. The line’s unit count reports the quantity administered in that measure.
Payers use the measurement code and unit count to verify dosage and pricing. Without a valid unit count, they can’t confirm the billed amount and may reject the claim, which can delay payment.
This edit – the industry’s term for an automated validation rule – catches the issue before it reaches the payer.
When this edit applies
A professional or institutional claim will fail this edit in the following cases:
JSON API
If you’re using one of Stedi’s JSON claim submission API endpoints, the edit fails if:A service line contains a
drugIdentification.measurementUnitCodevalue.
ANDThe service line’s
drugIdentification.nationalDrugUnitCountfield is less than or equal to”0”.
Raw X12
If you’re using raw X12, the edit fails if:Loop 2410(Drug Identification) is present
ANDThe
CTP-05(Composite Unit of Measure) ofLoop 2410contains a value.
ANDThe
CTP-04(National Drug Unit Count) ofLoop 2410is less than or equal to0.
Stedi portal
If you’re using the Stedi portal’s professional claim form, the edit fails if:Box 24 – Service Lines contains a service line with a Unit/Basis of measurement value and a Quantity less than or equal to zero.

Rejection errors
If you submit a claim that fails the edit using Stedi’s claim submission APIs or professional claim form, you’ll get back an error message in real time. If you’re using a JSON API endpoint, the response includes error details in the errors array:
{ "errors": [ { "code": "33", "description": "Invalid drug unit count. When reporting a drug unit qualifier, the drug count must be greater than zero (0.0). 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 contain a related claim status category code, claim status code, and error message. You can use the error message to correct and resubmit the 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.
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.