Claim attachments are additional documents that help justify or validate a claim. They’re typically required when the claim alone doesn’t provide enough information for the payer to make a decision, such as when a procedure is unusual, high-cost, or uses an unlisted code. Attachments can include medical records, treatment plans, radiographs, photographs, itemized bills, and letters from providers - the type required for each claim depends on the services listed and the payer’s rules. For example, a claim for a dental crown may require X-rays, while a claim for a surgery may require an operative report. There are two steps to sending 275 claim attachments through Stedi:
  1. Submit a claim that references the attachment(s) in the appropriate properties.
  2. Submit the attachment(s) with the required information to link them to the claim.
The payer will then process the claim and attachment(s) together.

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Transaction enrollment

Some payers require enrollment before allowing providers to submit 275 claim attachments. This enrollment process is separate from the transaction enrollment process for 837 claims. The Payer Network lists which payers require transaction enrollment for 275 claim attachments. Visit Transaction Enrollment for details about the transaction enrollment process.

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Solicited vs. unsolicited attachments

There are two types of claim attachments:
  • Solicited: The payer requests attachments for a submitted claim in a Request for Additional Information (277 RFA) transaction. In these cases, you must submit the attachment(s) in a separate 275 transaction that references the 277 RFA.
  • Unsolicited: The provider proactively sends attachments at their discretion without a prior request from the payer. In these cases, you must reference the attachment(s) in the claim submission and then submit the attachment as a separate 275 transaction.
You can only submit unsolicited claim attachments through Stedi APIs and SFTP. Check the Payer Network to determine which payers support attachments.

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Reference attachments in a claim

Before you can submit an unsolicited claim attachment, you must first submit a claim that references the attachment(s) in the appropriate location.

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Attachment level

You can specify attachments that relate to the entire claim or to a specific service line.
  • Entire claim: For all claim types, you can specify claim-level attachments in the claimInformation.claimSupplementalInformation.reportInformation object. This object corresponds to segment PWK in Loop 2300. API reference docs: professional | dental | institutional
  • Service line: For professional and institutional claims, you can specify service line attachments in the claimInformation.serviceLines.serviceLineSupplementalInformation object. This object corresponds to segment PWK in Loop 2400. API reference docs: professional | institutional

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Required properties

Both claim and service line attachments require the following properties to inform the payer that an attachment will follow the claim submission.
  • attachmentReportTypeCode: This code identifies the type of report or document you plan to submit as an attachment. Visit Code lists for a complete list of valid codes.
  • attachmentTransmissionCode: Set to EL when submitting attachments through Stedi. This property indicates the attachment will be sent in a separate, electronic 275 transaction.
  • attachmentControlNumber: This is a unique identifier for the attachment. The payer uses this identifier to match the attachment to the claim. We recommend using a ULID or UUID of up to 50 characters.

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Submit claim attachments (275)

Once you submit the claim, you can submit the attachment to the payer in a separate 275 transaction. The process for submitting claim attachments depends on whether you want to submit them in JSON or X12 EDI format.

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JSON

You can submit unsolicited claim attachments through Stedi JSON APIs. Submitting claim attachments in JSON requires three steps:
1

Create the claim attachment

Call the Create Claim Attachment (275) JSON endpoint to receive a pre-signed URL that you can use to upload the attachment file to Stedi.
2

Upload the attachment file

Use a PUT request to upload the attachment file to the pre-signed URL (uploadURL) in the response. The request must include a Content-Type header that matches the MIME type you specified for the attachment file.The following example shows how to upload a JPEG attachment:
curl --request PUT \
  --url "<uploadUrl>" \
  --header "Content-Type: image/jpeg" \
  --upload-file /path/to/file.jpeg
We recommend limiting attachments to 64MB each, but some payers may have different size requirements. When in doubt, check the payer’s documentation to determine their specific limits. Stedi stores uploaded files for 45 days. After that, you must reupload the attachment file before you can submit it to the payer.
3

Submit the attachment to the payer

Call the Submit Claim Attachment (275) JSON endpoint to submit attachments to the payer. You must include specific properties in your request to link the attachment to the correct claim.Stedi generates the X12 EDI 275 transaction, sends it to the payer, and returns summary information about the submission.
You must supply the following information in your Submit Claim Attachment (275) JSON request to link the attachment to the correct 837 professional, dental, or institutional claim:
PropertyDescription
relatedTransactionId or relatedExecutionIdAn identifier for the 837 claim you previously submitted through Stedi. This value tells Stedi which claim is related to the attachment.
attachmentIdThe attachment ID you received in the Create Claim Attachment (275) JSON response. This value tells Stedi which file to use when generating the 275 transaction for the payer.
providerAttachmentControlNumberThe value you set in the claim’s attachmentControlNumber property. It allows the payer to associate the attachment with the claim that’s already in their system.
providerControlNumberThe value you set in the claim’s providerControlNumber property. This property is optional and allows you to indicate that the attachment should be associated with only a specific service line from the claim. This doesn’t apply to dental claims.

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X12 EDI

You can submit unsolicited claim attachments in X12 EDI format through the API or SFTP. We recommend this approach when you have an existing system that generates X12 EDI files and you want to send them through Stedi. When you send the attachment in X12 EDI format, you don’t need to upload it to Stedi first - you can send the entire 275 transaction directly to the payer.

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API submission

Call the Submit Claim Attachment (275) X12 EDI endpoint with a payload in 275 X12 EDI format. Stedi sends the 275 transaction to the payer and returns summary information about the submission.
  • Payer ID: You must submit a payer identifier in Loop 1000A NM109 so Stedi can route the attachment to the correct payer. This identifier must be a payer ID or payer ID alias listed in the Payer Network. For example, you could use 60054, HPQRS, AETNA, or any other listed payer ID alias for Aetna.
  • The size limit for attachments submitted in a single API request is 6MB. If you need to submit larger attachment files, you must submit them through Stedi SFTP or the JSON endpoints.

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SFTP submission

Submit the 275 transaction to the payer through Stedi SFTP. This is ideal if you have attachments that are larger than 6MB. We recommend limiting attachments to 64MB each, but some payers may have different size requirements. When in doubt, check the payer’s documentation to determine their specific limits.

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Payer responses

The payer processes claims and claim attachments together. When you submit a claim attachment, you’ll receive the same 277CA and 835 ERA responses for the claim as you would for a regular claim submission. If a claim is rejected, pended, or denied due to issues with attachments, you’ll likely receive error codes in the 277CA response that indicate the issue. However, the exact error codes used depend on the payer’s system and how they handle attachments.