Institutional Claims · CMS-1450

UB-04 ↔ 837I Crosswalk

A field-level map from the paper UB-04 (CMS-1450) institutional claim form to the ASC X12N 837I electronic claim (version 005010X223A2). Each form locator is matched to its EDI loop, segment/element, and qualifier, with plain-language descriptions on both sides.

Form Locator → EDI Map

837I v5010A2
FL Paper Form Block Paper Description Loop Segment / Element Qualifier EDI Description
How to read this. Notation follows the ASC X12 implementation guide: a loop (e.g. 2010AA) contains segments (e.g. NM1), each made of elements (e.g. NM103 = the 3rd element of NM1). Composite elements use a dash (e.g. HI01-2 = the 2nd sub-element of the first HI position). A qualifier is a code that tells the receiver what the data means — e.g. HI01-1=BG flags a Condition Code, and NM101=71 identifies the Attending Provider. Where the paper claim repeats a field (condition, occurrence, value, diagnosis, procedure lines) the EDI side repeats the composite positions (HI01, HI02, …).

Scope & sources. Mapping reflects the ASC X12N 837I 005010X223A2 Technical Report and a Medicare MAC's published CMS-1450 crosswalk. UB-04 form locator names and code sets are maintained by the National Uniform Billing Committee (NUBC) and the American Hospital Association (AHA); descriptions here are simplified summaries for reference, not the official NUBC definitions. Some locators are payer-specific or not required by Medicare (e.g. FL38, FL43 description, FL66, FL81), and FL07, 30, 37, 49, 68, 73, and 75 are reserved for future use. Always confirm against your payer's companion guide and the official NUBC UB-04 manual before submitting claims.