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 Reading 837 Error Reports and Making Corrections Issue #4
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This e-mail newsletter, Reading 837 Error Reports and Making Corrections, is the fourth in the series Electronic Transactions…It's Easier Than You Think. Electronic Transactions not only make good business sense but they are also the law. Therefore, IHS is producing detailed and simple-to-use training materials to help you successfully meet the requirements for HIPAA electronic transactions and code sets. To review the previous three newsletters, click here for Newsletter #1, click here for Newsletter #2, or click here for Newsletter #3.

The Electronic Transactions series includes an introductory newsletter and four topic newsletters:
  • Preparing to Test the 837
  • Testing the 837
  • Reading 837 Error Reports and Making Corrections
  • Testing and Posting the 835 Remittance

In the previous newsletters you learned how to get ready for the testing process and then how to complete testing and begin production. In this newsletter you will learn how to read error reports and make corrections so that your claims will be processed.

A New Favorite Place
Become familiar with IHS' HIPAA web site at http://www.ihs.gov/AdminMngrResources/HIPAA/index.cfm. In particular, you will want to know what is in the Electronic Reading Room.
This newsletter is particularly relevant for people in the Business Office. To learn about reading error reports and making corrections:


The 837 Transaction file is the file that you submit to an insurer. It contains all the claim information. This includes all of the claim data of a created batch. In order to identify errors in the 837, you need to be familiar with the 837 format and how to interpret it.

In the PowerPoint presentation accompanying Newsletter #2, Preparing to Test the 837, the components of the 837 were described: data element, data segment, loop, transaction set, header, and trailer. Delimiters are the characters that separate two elements and terminate a segment.

In this newsletter you will:

  • Become familiar with the data layout of the 837.
  • Learn how to read an error report rejecting a claim.
  • Learn how to correct the error and resubmit the claim.

837 Data Layout

The data layout of an 837 file may look confusing at first due to the electronic format, but the data are the same data you are accustomed to seeing in the UB-92 or the HCFA-1500 forms. The overall data stream of an 837 file is known as a Transaction Set.

Transaction Set Sections

The Transaction Set is divided into sections. Each section provides a specific kind of information. The sections are:

  • Transaction Header
  • Billing Provider Detail
  • Subscriber Detail
  • Patient Detail
  • Claim Detail
  • Transaction Trailer

Data Segments and Elements

Every section of the Transaction Set contains data segments. Segment names begin each line of detail. A segment name is two or three alphabetical characters. In the example below, the segments names are in bold.

Each segment contains data elements. Data elements are the same as the data provided by each individual Form Locator position on the UB-92 or the HCFA-1500 claim forms. The number of elements varies depending on the segment's purpose. Data elements are separated by asterisks (delimiters). In the example below, the ST segment has two elements and the BHT segment has six elements.

Counting Data Elements

In order to correct errors in an 837, you need to know how to count the data elements. Element counts begin to the right of the segment. In the above example:

STØ1 is the first set of data between asterisks. STØ1 is "837."
BHTØ3 is the third set of data between asterisks. BHTØ3 is "1Ø1537."
Your best friends in interpreting the 837 are the HIPAA Implementation Guides and Addenda. By now you should have downloaded them, printed them out, and put them where you are going to need them.

The Quick Reference Guide (Download Acrobat Reader) shows a typical billing scenario and how it looks when presented in the 837 format. The 837 data string is broken out line-by-line so you can see the loops, segments, and data elements.

When viewed on screen, the 837 file is one long data stream. This can be very difficult to read. The Quick Reference Guide explains how to convert this file into line items that are easier to troubleshoot.

Get to Know the Implementation Guides and Addenda

Three Different Guides/Addenda

There are three versions of the Implementation Guides and Addenda. Each has an alphanumeric code. The last two digits distinguish one 837 file from another.

Institutional: 004010X096
Professional: 004010X098
Dental: 004010X097

Segments and elements may be different in each guide. Use the correct guide for your batch type. To learn what elements are required for a segment:

  1. Find the segment listed in the appropriate Implementation Guide's Table of Contents.
  2. Go to the given page.
  3. You will find the loop name, whether the segment is required or situational, the data elements required in the segment and how to enter them, and the order of the elements.

Required or Situational

Loops, segments, and elements can be required or situational. If required, it is mandatory that this information is included. The claim will be rejected if the information is not included.

Situational information is information that may or may not be needed depending on the claim's criteria.

Each Implementation Guide explains what information is required and what is situational.

Loops Are Important

Each 837 file is broken into sections of data. These sections are called loops. Each loop has a particular focus, e.g., Submitter Name, Billing Provider Name, Claim Level Information, Service Line. The data stored within loop sections are similar to that stored in Patient Registration or Fileman files.

Some data segments repeat. For example, there could be several address lines - for the Billing Provider, the Subscriber, the Patient, etc. The segment identifier for every address is N3.

However, each of these address lines will be in a different loop:

Segment N3 of loop 2Ø1ØAA has the Billing Provider address.
Segment N3 of loop 2Ø1ØBA has the Subscriber address.

Note: Not all the loops will be the same for all three Implementation Guides and Addenda.

The loop number tells you which address caused an error and which section of the claim needs to be edited. The loop number has four digits and often is followed by one or two alphabetical characters: 2400, 2010BB.

The Error Report

Types of Reports

The 997 Functional Acknowledgement is the generally recognized response to the 837 electronic transaction. It indicates whether the file was accepted or rejected.

In some instances, other error report formats are used. Arizona Medicaid has adopted a format called the 824. There are also other report formats used by clearinghouses and private insurers.

How Do You Get the Error Report
Instructions for retrieving the error report can be found in the Companion Guide. If you are working with a clearinghouse, it will provide instructions.

997 Format

The 997 format is somewhat different from the 837 format. On a 997 file, the segments after the header all begin with AK. The data elements are counted in the same way they are for an 837 file.

The AK Segments (below in bold) indicate whether the file was accepted or rejected.

  • If the file passed, it contains an "A" for accepted in the first element of the AK5 and AK9 segments.
  • Files that have only AK5 and AK9 segments are error free and need no further attention.
  • If the file is rejected, it contains an "R" for rejected in the AK5 and AK9 segments.
  • Files that have been rejected are the only files that display the AK3 and AK4 segments.
  • AK3 and AK4 segments occur for each error found. There are two errors below.
  • The AK3 and AK4 segments on the 997 report show the user the location (loop, segment, element, line) of the error on the matching 837 file.

Match 837 and 997 Files

In order to confirm whether batches were accepted or rejected by an insurer, you must be able to identify which batches passed and which batches failed. You must also be able to match the rejecting 997 to the 837 file. Here are some key things to learn to look for.

  1. Batch number
    The 837 is assigned an individual batch number when the batch is created. The corresponding 997 file will contain the same batch number.
    • On an 837 file, BHT03 contains the batch number.
    • On a 997 file, AK102 contains the batch number.
  2. 837 or 997
    On both an 837 and a 997, ST01 identifies the type of file (837 or 997).
  3. Dates and times
    Dates and time of file transmissions are stored in the Header elements of each file. This information can also be used to identify file batches.
  4. Type of file
    The files can also be identified as institutional (…096), professional (…098), or dental (…097) by the alphanumeric code that corresponds to the Implementation Guides.

These two files match: same batch number, same date and time, and same type of file.

Find the Errors

Errors can result from one or more of the following:
  • Incorrect formats
  • Missing information
  • Incomplete information

See the Quick Reference Guide (Download Acrobat Reader) for common data errors that cause an 837 claim to be rejected.

The AK3 and AK4 Segments

Remember that the AK3 and AK4 segments on the 997 report show the user the location (loop, segment, element, line) of the error on the matching 837 file. The table below shows what information can be found in the first error for the 997 report below.

Data Element
What It Tells You
AK301 DTP Segment that contains an error on 837
AK302 242 Line number of 837 file where DTP segment will be located
AK303 2300 Loop where the DTP segment will be found
AK401 03 Actual element where the error is found
AK404 20040419- Copy of the data in error

Tip: The combination of AK301 and AK401 show the segment and element where the error will be found on your 837 file.

Use the HIPAA Implementation Guide and the 837 to Identify the Error and Error Reason

This is what you know so far about the example above:

  • There are two DTP03 errors.
  • The errors occur on lines 242 and 253 of the 837 file.
  • Both errors occur in the 2300 loop, the Claim Information loop.
  • You also know what the incorrect data look like.
Here's the bottom line: You will not be able to identify the error and the reason for the error without the HIPAA Implementation Guide and the 837.

To identify the error in a 997 and to determine how to fix it:

  1. In the HIPAA Implementation Guide, find the Transaction Set listing.
  2. Scan through the tables to find the right loop.
    (In this case, it is 2300.)
  3. Find the segment listing with the error.
    (In this case, it is DTP.)

    NOTE: In some cases, there is more than one segment with the same name. The 997 does not provide detail on which one is causing the error.
    (In Loop 2300 for the 837-I there are three DTP choices. DTP stands for "date or time period.")

  4. On the 837 file that matches the 997, locate the segment on the line indicated.
    (In this case, you know that the segments are on lines 242 and 253.)
  5. Find the data in the first element of the segment line. This code will direct you to which type DTP segment contains the error. This step will only occur in cases where there are multiples of the segment name within the same the loop.
    (In this case, it is element 434.)
  6. In the HIPAA Implementation Guide, move ahead several pages to the details showing segments and their elements. Scan down the list until you find the segment you are looking for that contains the code you are looking for in the first element.
    (In this case, the segment is DTP and the first element data is 434. DTP*434 relates to Statement Dates.)
  7. The data in AK404 on the 997 will be a copy of the error data from the identified element on the 837. That is the data that needs to be corrected.
    (In this case, it is the date. Dates and times must be in the correct format [CCYYMMDD] and must be complete to avoid rejection.)
  8. The Implementation Guide explains the correct format for the data.
    (In this case, the Statement Date only has the "from statement date." "Through date of service" is also required for this field. The claim was rejected for incomplete information.)

Correct Errors and Resubmit Files

The final step is to correct the rejected claim and resubmit it.

Correct Errors in RPMS

Since the 837 file includes multiple claims run together, the first step is to locate the claim number for the problem claim. Here is what you need to know to find the claim number:

  1. The value in HL01 element provides a count for each HL segment and will increment by 1 for each HL segment found. The Header contains the first HL segment and begins the count for each HL segment afterwards.
  2. To find a claim number, locate the CLM segment within the claim data that contains the error.
    (For this example, the CLM segment is in the claim that includes line 242.)
  3. The claim number is provided in the first element (CLM01).
    (For this example, the claim number is 906311A-BE.)

Make the correction to the identified claim in RPMS.
(In this example, the "through date of service" needs to be added.)

Recreate and Resubmit the Batch

Once all errors have been identified and appropriately corrected, recreate the batch(es) and resubmit the files to the insurer in the next submission. The process for recreating batches remains unchanged. It is important to remember that changes made to the claims will not reflect on the new 837 transmission unless the batch was recreated prior to transmitting the new file.


  • As you become more acquainted with the 837 and 997 files and the Implementation Guides, the process will speed up. You will learn to recognize common and recurring errors and be able to quickly resolve them.
  • The error correction process is not simple but it can be mastered. Some sites have found it expedient to designate one person to correct all errors.
  • Each recreated batch gets a new RPMS number.
  • Make sure to only include corrected claims in a recreated batch.
  • Monitor your error reports carefully. Check every batch in a report. Resubmit all errors. Until a claim is submitted correctly, the insurer has no record of the claim.
  • If 20 claims are rejected for one patient, it could be as simple as a name entered wrong in one place. The error must be corrected at the source as well as on the claim so that it doesn't repeat.
  • It is important to note the differences between insurers when resubmitting previously rejected claims.
    • Medicare: Only the rejected claims do not pass. Therefore, only resubmit the rejected claims, not the entire batch.
      For example: 100 claims sent, 2 rejected means that Medicare has accepted 98 claims. After correcting, resend the 2 rejected claims. If the entire batch were resent, there would be 98 duplicated claims to Medicare.
    • Medicaid: Any rejected claim causes the entire batch to fail. Correct the rejected claim(s). Recreate and resubmit the entire batch.
    • Private Insurance: This will be insurer specific. Ask each insurer how they will process files with rejects. Determine if an entire batch will fail, or if only the rejected claims fail.


IHS HIPAA website
Implementation Guides and Addenda

Where Are We Now?

IHS tracks the testing status of business transactions. To see the current testing status, click here.


This newsletter is one in a series of six on the topic "Electronic Transactions . . . It's Easier Than You Think." Each of the newsletters is associated with a PowerPoint presentation expands on the contents of the newsletter in a format that supports self-paced or group training. Even greater technical detail is presented in two Quick Reference Guides: "Working with the 837 Transaction" and "Working with the 835 Remittance Advice." Electronic versions of these materials are available on the IHS Electronic Transactions website at www.ihs.gov/AdminMngrResources/HIPAA/index.cfm. A training resources binder includes printed copies of these materials and a CD-ROM with electronic copies of the files.


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