How many blocks are in CMS-1500?

The CMS-1500 claim form contains 33 numbered blocks (or boxes), numbered from 1 to 33.

• Patient and Insurance Data: Blocks 1 through 13 cover demographic and insurance information.
• Claim and Condition Details: Blocks 14 through 23 cover condition, treatment, and authorization details.
• Service Lines: Block 24 includes six individual service lines (24A through 24J) for specific procedures and diagnosis codes.
• Provider Billing Information: Blocks 25 through 33 capture provider identifiers, total charges, signatures, and facility location details.

You can review a full breakdown of the layout and box instructions using the CMS 1500 Claim Form Instructions Tool.

You should not fill out the CMS 1500 form by hand.

Why Handwriting Is Not Allowed

• Scanner Rejections: Insurance companies use Optical Character Recognition (OCR) machines to read claims. These scanners cannot read messy or handwritten text well.
• Processing Delays: Handwritten forms often cause errors. This leads to claim denials or slow payments.
• Payer Rules: Most insurance payers and Medicare require typed, computer-printed, or electronic submissions (837P formats).

Best Practices for Paper Submissions

• Use a Printer: Print forms using a laser or inkjet printer with true black ink.
• Use Correct Fonts: Type in all uppercase letters using standard fonts like Courier New or Times New Roman.
• Use Original Paper: Always print on the official red-and-white CMS 1500 (02/12) scannable form. Photocopies or black-and-white copies are rejected.

The CMS-1500 claim form contains 33 numbered fields (boxes) used by healthcare providers to bill insurance companies for professional services.

The boxes are organized into four main sections from top to bottom:

Patient and Insurance Information (Boxes 1–13)

• Boxes 1–1a: Type of health insurance coverage (Medicare, Medicaid, Group Health Plan) and the insured’s identification number.
• Boxes 2–3: Patient's full legal name, date of birth, and gender.
• Boxes 4–7: Insured's name, patient address, relationship to the insured, and insured's address.
• Box 8: Reserved for National Uniform Claim Committee (NUCC) use (left blank).
• Boxes 9–9d: Information for secondary or other insurance policies.
• Boxes 10a–10d: Indications of whether the patient's condition is related to employment, auto accidents, or other accidents.
• Box 11: Primary policy or group number.
• Boxes 12–13: Patient and insured signatures (or "signature on file") authorizing the release of medical information and assignment of benefits.

Condition and Clinical Context (Boxes 14–23)

• Boxes 14–15: Dates of current illness, injury, or pregnancy, along with required qualifiers.
• Box 16: Dates the patient was unable to work.
• Boxes 17–17b: Name of the referring or ordering provider and their National Provider Identifier (NPI).
• Box 18: Related hospitalization dates.
• Box 19: Additional local use or extra processing information.
• Box 20: Outside lab charges and indicators.
• Box 21: Up to 12 ICD-10-CM diagnosis codes (labeled A through L).
• Box 22: Resubmission code and original reference number.
• Box 23: Prior authorization or referral number.

Service Details (Boxes 24A–24J)

This middle grid contains rows for individual service lines, detailing dates of service, place of service codes, CPT/HCPCS procedure codes, modifiers, diagnosis pointers (linking to Box 21), charges, units, and the rendering provider's NPI.

Provider and Billing Information (Boxes 25–33)

• Box 25: Provider or organization Federal Tax ID (EIN or SSN).
• Box 26: Patient account number.
• Box 27: Acceptance of assignment checkmark.
• Box 28: Total charges for the claim.
• Box 29: Amount paid by another payer.
• Box 30: Reserved for NUCC use.
• Box 31: Physician or supplier signature and date.
• Box 32–32b: Service facility location name, address, and NPI (where services were performed).
• Box 33–33b: Billing provider's name, address, phone number, and group NPI (who is getting paid).

The main difference is that the CMS-1500 form is used by individual healthcare professionals for professional services, while the UB-04 form is used by institutional facilities for facility charges.

Key Differences

• Provider Type:
  • CMS-1500: Used by individual doctors, therapists, and non-institutional providers.
  • UB-04: Used by hospitals, nursing facilities, and ambulatory surgery centers.
• Service Setting:
  • CMS-1500: Focuses on outpatient care and professional procedures.
  • UB-04: Handles inpatient stays, room and board, and complex facility services.
• Form Structure:
  • CMS-1500: Contains 33 fields.
  • UB-04: Contains over 80 fields (81 fields) to account for detailed facility costs.
• Coding Systems:
  • CMS-1500: Uses CPT/HCPCS codes for specific medical procedures.
  • UB-04: Uses revenue codes, occurrence codes, and value codes.
• Medicare Compatibility:
  • CMS-1500: Maps to Medicare Part B.
  • UB-04: Maps to Medicare Part A.

The CMS-1500 claim form contains 33 numbered boxes (also referred to as fields or items).

The form breaks down into two main sections:

• Patient and Insured Information (Boxes 1–13): Captures insurance type, patient demographics, relationship to the insured, and authorization signatures.
• Physician and Supplier Information (Boxes 14–33): Captures clinical data, dates of service, diagnosis codes, procedure codes, charges, and provider identification details (such as the NPI and Tax ID).