The table below includes external code lists maintained by X12 and external code lists maintained by others and distributed by WPC on behalf of the maintainer. Click on the name of any external code list to access more information about the code list, view the codes, or submit a maintenance request. These external code lists were previously published on either www.wpc-edi.com/reference or www.x12.org/codes. If you have questions about the X12-maintained lists, submit them on the X12 Feedback form.
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| Name | ID | Scope Statement | Maintained by | Last Modified |
|---|---|---|---|---|
| Birth Sex Codes | 1002 | These codes describe the sex that a medical practitioner used to describe an individual at birth. | CMG01 | 08/11/2026 |
| Claim Adjustment Group Codes | 974 | These codes categorize a payment adjustment. | CMG01 | 05/20/2018 |
| Claim Adjustment Reason Codes | 139 | These codes describe why a claim or service line was paid differently than it was billed. | CMG03 | 11/01/2025 |
| Claim Status Category Codes | 507 | These codes organize the Claim Status Codes (ECL 508) into logical groupings. | CMG03 | 03/03/2020 |
| Claim Status Codes | 508 | These codes convey the status of an entire claim or a specific service line. | CMG03 | 03/01/2025 |
| Clinical Care Parameter Codes | 1011 | These codes identify a clinical parameter, also described as a biological label based on genetic factors. | CMG01 | 08/11/2026 |
| Clinical Care Parameter Qualifier Codes | 1010 | These codes identify the type or category of a clinical care parameter. | CMG01 | 08/11/2026 |
| Error Reason Codes | 977 | These codes describe a processing error related to a particular EDI transmission. | CMG02 | 11/01/2025 |
| Gender Identity Codes | 1005 | These codes convey an individual’s personal sense of being a man, woman, boy, girl, nonbinary, or something else. | CMG01 | 08/11/2026 |
| Individual Relationship Codes | 1069 | These codes indicate the relationship between two individuals or entities. | CMG01 | 08/11/2026 |
| Industry Specific Remark Codes | 973 | These codes convey information about remittance processing or further explain an adjustment already described by a Claim Adjustment Reason Code (CARC) from ECL 139. | CMG01 | 06/01/2020 |
| Insurance Business Process Application Error Codes | 895 | These codes report application warnings and errors for insurance business processes. | CMG02 | 07/12/2024 |
| Insurance Descriptor Codes | 979 | These codes describe, identify, or clarify the insurance being reported in an eligibility and benefits response. | CMG01 | 07/01/2026 |
| Issuer Codes | 1009 | These codes identify the issuer of a document that conveyed an individual’s sex or gender. | CMG01 | 08/11/2026 |
| Payment Type Codes | These codes identify the type and purpose for a payment amount. | CMS | 03/01/2021 | |
| Pronoun Code Sets | 1006 | These codes convey an individual’s preferred word or words that can replace their name in communications (aka pronouns). | CMG01 | 08/11/2026 |
| Property & Casualty Code Lists | These codes are used by Property & Casualty organizations | WPC | 01/31/2022 | |
| Provider Adjustment Reason Codes | 967 | These codes report payment adjustments that are not related to a specific claim, bill, or service. | CMG01 | 07/01/2025 |
| Provider Taxonomy Codes | 682 | These codes define the health care service provider type, classification, and area of specialization. | NUCC | 07/01/2025 |
| Race and Ethnicity Categories | 861 | These codes describe an individual's race or ethnicity. | CMG01 | 08/11/2026 |
| Recorded Sex or Gender | 1007 | These codes represent an individual’s recorded sex or gender and associated attributes. | CMG01 | 08/11/2026 |
| Remittance Advice Remark Codes | 411 | These codes provide additional explanation for an adjustment already described by a Claim Adjustment Reason Code (CARC) or convey information about remittance processing. | CMS | 07/01/2026 |
| Report Type Codes | These codes provide exchange-related report type codes. They define the type of report being described. | CMS | 04/26/2024 | |
| Service Review Decision Reason Codes | 886 | These codes communicate the reason for the health care services review outcome. | CMG01 | 07/01/2026 |
| Service Type Codes | 958 | These codes identify business groupings for health care services or benefits. | CMG01 | 07/01/2026 |
| Service Type Descriptor Codes | 981 | These codes further clarify a benefit response which cites a Service Type Code (ECL 958). | CMG01 | 04/01/2020 |
| Sex Codes | 1003 | These codes document a specific instance of sex or gender information. | CMG01 | 08/11/2026 |
| Sexual Orientation Codes | 1004 | These codes convey an individual’s sexual orientation in relation to the pattern of emotional, sexual, and romantic attraction. | CMG01 | 08/11/2026 |
| Source Document Codes | 1008 | These codes represent the type of document that identified an individual’s sex or gender. | CMG01 | 08/11/2026 |