ANSI X12 837P - 4010 2300 PWK - Claim Supplemental Information

The PWK (Paperwork) segment in the 2300 loop of the X12 837 (4010) professional claim is used to indicate that additional documentation is being submitted or is available to support the healthcare claim. This segment links the claim to attachments such as medical records, operative notes, or consent forms.

The PWK segment is situational and should only be reported when required by the payer or trading partner. Providers should always confirm with the payer if attachments are necessary and follow their required submission process.

Sample 837P (4010) – 2300 PWK Segment

In the example PWK*OB*FX***AC*ACD123~:

• OB – Report Type Code indicating an Operative Note.
• FX – Report Transmission Code indicating the documentation was sent by fax.
• PWK03–PWK04 – Not used in this example.
• AC – Identification Code Qualifier, meaning the following value is an Attachment Control Number.
• ACD123 – The control number associated with the faxed document.

Reminder: Confirm with the payer if the attachment is required and how the control number should be referenced. Payer rules may vary under the 4010 implementation.

Note: The PWK segment should not be included unless documentation is required. Be sure to follow payer-specific guidance on submission formats and control number usage.