CMS-1500 reference
The CMS-1500, box by box, for chiropractors.
By Dr. Daniel Turner, DC · Reviewed September 2, 2026
Every box on the claim form, what belongs in it, the chiropractic specific traps, and the exact denial codes each mistake produces, cross linked into the denial library. Written from a practice that files these claims daily.
| Box | What it carries |
|---|---|
| Box 1 and 1a | Insurance type and insured ID number |
| Box 2 | Patient name |
| Box 3 | Patient birth date and sex |
| Box 4 | Insured name |
| Box 5 | Patient address |
| Box 6 | Patient relationship to insured |
| Box 7 | Insured address |
| Box 9 and 9a to 9d | Other insured information |
| Box 10a to 10c | Is the condition related to employment, auto accident, or other accident |
| Box 10d | Claim codes |
| Box 11 and 11a to 11d | Insured policy group number and related details |
| Box 12 | Patient or authorized signature |
| Box 13 | Insured signature, assignment of benefits |
| Box 14 | Date of current illness, injury, or pregnancy |
| Box 15 | Other date |
| Box 16 | Dates patient unable to work |
| Box 17, 17a, 17b | Referring provider and NPI |
| Box 18 | Hospitalization dates |
| Box 19 | Additional claim information |
| Box 20 | Outside lab |
| Box 21 | Diagnosis codes |
| Box 22 | Resubmission code and original reference number |
| Box 23 | Prior authorization number |
| Box 24A to 24J | The service lines |
| Box 25 | Federal tax ID |
| Box 26 | Patient account number |
| Box 27 | Accept assignment |
| Boxes 28, 29, 30 | Total charge, amount paid, balance |
| Box 31 | Signature of physician |
| Box 32, 32a, 32b | Service facility location |
| Box 33, 33a, 33b | Billing provider info and NPI |
The companion libraries
When a box goes wrong, the payer answers with a CARC code: the denial code library has the fix for each. The services the boxes describe live in the CPT library, and the diagnoses that fill Box 21 in the ICD-10 library.
General information for billing teams. The NUCC 1500 instructions and payer companion guides control for any individual claim.
Common questions
What is the CMS-1500 form?
The CMS-1500 is the standard paper claim form for outpatient professional services in the United States, maintained by the NUCC, and the electronic 837P transaction mirrors its content. Every box maps to specific claim data: who the patient and insured are, what was diagnosed and done, and who should be paid.
Which CMS-1500 boxes cause the most chiropractic denials?
In chiropractic billing the heavy hitters are Box 24 (modifiers, diagnosis pointers, and units on the service lines), Box 21 (diagnosis codes supporting the CMT regions billed), Box 22 (resubmission coding, whose absence turns corrected claims into duplicates), Box 10 (accident questions on personal injury cases), and Box 33 (the group versus individual NPI decision).