Overview

When you receive a rejection or denial from a payer, they often speak in terms of loops, segments, and elements. This refers to the coding of the 837 EDI file that was sent to them. Every EDI file is different, but this article can give you a general idea of what you're actually looking at. First, you'll need to know how to find the file itself.

1. Navigate to Filing > CMS-1500.
2. Find the electronic claim you want to view and select the  icon.
3. Click View EDI File.

Anatomy of an EDI (837) File

A block or section of an EDI file is called a Loop. Each loop contains several different Segments, which are comprised of Elements and Sub-Elements.

Loops

A Loop is a set of information about a claim. For example, the billing provider information is contained in a Loop. The service lines are included in a Loop. Although Loops are the biggest component in an EDI, they are often the hardest to distinguish. They will typically begin with an HL or NM1 Segment. While there are several different Loops, they can be broken into 5 main sections:

1. 2000A = Billing Provider
2. 2000B = Subscriber
3. 2000C = Client (Only present if different from Subscriber)
4. 2300 = Claim Information
5. 2400 = Service Line Information

Segments

Segments provide more specific information about the claim. Each Segment is separated onto its own line, making it a lot easier to read.

Each line ends with a tilde (~), called a Segment Separator, and every Segment begins with a Segment Identifier Code.

Common codes that you will see throughout the file include:

• PRV = Provider
• SBR = Subscriber
• NM1 = Name
• N3 = Street Address
• REF = Reference
• CLM = Claim

Other codes that may be included:

• N4 = City, State, and ZIP
• DTP = Date
• DMG = Demographic
• HL = Hierarchy
• LX = Line
• SV1 = Service

Elements

Each Segment line consists of Elements, separated by asterisks (*), also known as Element Separators.

Additionally, Sub-Elements are separated using a colon (:). If you see multiple asterisks or colons side-by-side, that means that the Element or Sub-Element is empty.

As with Segments, there are also several Element Identifier Codes that you will see throughout the file, such as:

• 41 = Claim Creator (Hardcoded to EI Assistant)
• 40 = Claim Receiver
• 85 = Billing Provider
• 82 = Rendering Provider
• DN = Referring Provider
• IC = Information Contact
• 77 = Service Location
• 472 = Date of Service
• SY = Social Security Number
• EI = Tax ID (EIN)
• XX = NPI
• Y4 = Claim Casualty Number
• HC = Standard CPT Code
• ABK = Principal Diagnosis
• ABF = Diagnosis

Each Element is named using a 2-digit number, and Sub-Elements use a single digit. Elements and Sub-Elements are attached to the Segment Identifier Code when being referenced.

Example: Loop 2300, HI02-1

• HI = Segment Identifier Code
• 02 = Element
• 1 = Sub-Element

Ready to discover more?

When you have grasped the basic structure of the EDI file, you will want to break down each loop and segment so you know exactly what you are looking at and how it correlates to a CMS-1500 form. For more information, please see:

Loop 2000A - Billing Provider

Loop 2000B - Subscriber

Loop 2300 - Claim Information

Loop 2400 - Service Line Information

Secondary Payer Format

837 vs CMS-1500: Inclusion Rules