TL;DR
Chapter 25 of the Medicare Claims Processing Manual gives Medicare's instructions for the institutional claim, Form CMS-1450, known in the industry as the UB-04, and its electronic counterpart. It walks through the form locators in order and says which are required, which are situational and which Medicare does not use, so hospitals, SNFs, home health agencies and other institutional providers know what each field must contain.
Chapter 25 at a glance
- Current revision
- Rev. 12423
- Issued December 20, 2023
- Effective
- January 1, 2024
- Implemented January 2, 2024
- Sections
- 12
- 4 top-level sections
- Transmittals in history
- 39
- Listed at the end of the chapter
- Monthly searches
- 40
- Google Ads, US, October 2026
What chapter 25 governs for billing
The CMS-1450 is the paper form behind the institutional claim, and the National Uniform Billing Committee maintains the data set; chapter 25 adds Medicare's requirements on top of it. Section 70 explains uniform billing with the form and what happens to its copies, and section 75 starts with general instructions that apply to every form locator: which providers use it, how fields are marked required or situational, and the fact that most Medicare institutional claims must be sent electronically.
Sections 75.1 to 75.6 then go through the form locators in order. The header fields identify the provider, the patient and the claim, including the type of bill in form locator 4 and the statement covers period. Form locators 18 to 41 carry condition codes, occurrence codes and spans and value codes, which tell the claims system about the admission, the accident or other liability circumstances, benefit days and amounts. Form locator 42 begins the line items, with revenue codes, HCPCS codes or HIPPS rate codes in form locator 44, service dates, units in form locator 46 and total and noncovered charges.
The lower part of the form holds the payer, insured and authorization information, the billing provider NPI in form locator 56, the principal and other diagnosis codes, the admitting diagnosis in form locator 69, procedure codes and dates in form locator 74 for inpatient claims, and the attending, operating and other provider identifiers starting at form locator 76. A December 2023 transmittal added the condition code hospitals use to identify intensive outpatient program services.
Sections billing teams use most
Section numbers and headings are CMS's; the notes are ours. Each section number opens the official chapter 25 PDF at the page where that section starts.
| Section | CMS heading | Why it matters |
|---|---|---|
| 75 | General Instructions for Completion of Form CMS-1450 for Billing | General instructions for completing the CMS-1450 for Medicare billing. |
| 75.1 | Form Locators 1-15 | Form locators 1 to 15: provider, patient, type of bill and statement period. |
| 75.2 | Form Locators 16-30 | Form locators 16 to 30: discharge hour, patient discharge status, condition codes and accident state. |
| 75.3 | Form Locators 31-41 | Form locators 31 to 41: occurrence codes, occurrence spans, responsible party and value codes. |
| 75.5 | Form Locators43-65 | Form locators 43 to 65: line details, payer, insured and NPI fields. |
| 75.6 | Form Locators 66-81 | Form locators 66 to 81: diagnoses, procedures and provider identifiers. |
How chapter 25 shows up on claims and denials
Most CMS-1450 problems are front-end rejections. A missing or invalid required form locator returns the claim as unprocessable with reason code 16 and a remark code that points at the field, and the provider corrects and resubmits it rather than appealing. A HCPCS code missing where Medicare requires one on an outpatient line returns remark M20.
Some errors change payment rather than processing. Condition, occurrence and value codes decide benefit days, liability and coordination with other insurers, and the type of bill must be consistent with the services and place of service, otherwise the claim can be denied with reason code 5. Before resubmitting, compare the claim with the chapter 25 instructions for the specific form locator and with the billing chapter for the provider type.
Codes you are likely to see on the remittance when a claim runs into this chapter's rules. The code pages explain each code's meaning, root causes and the usual fix.
| Code | Type | When it appears |
|---|---|---|
| 16 | Claim adjustment reason code | Required form locator missing or invalid; the claim is returned as unprocessable. |
| M20 | Remark code | Missing or invalid HCPCS on a line that requires one. |
| 5 | Claim adjustment reason code | Type of bill or procedure inconsistent with the place of service. |
| M51 | Remark code | Missing, incomplete or invalid procedure code. |
Current revision and recent transmittals
The chapter PDF posted on cms.gov is current through Rev. 12423, issued December 20, 2023, effective January 1, 2024, implemented January 2, 2024 (change request 13222). That revision changed section 75.5 (Form Locators43-65). Its subject line reads: “Enforcing Billing Requirements for Intensive Outpatient Program (IOP) Services with New Condition Code 92”.
The newest rows of the transmittal history printed at the end of the chapter (39 revisions in all). Rows whose subject could not be read reliably from the PDF table are left out; the PDF has the complete list.
| Revision | Issued | Subject | CR |
|---|---|---|---|
| R12423CP | December 20, 2023 | Enforcing Billing Requirements for Intensive Outpatient Program (IOP) Services with New Condition Code 92 | 13222 |
| R10880CP | August 6, 2021 | Internet Only Manual Updates to Pub. 100-01, 100-02, and 100-04 to Implement Consolidated Appropriations Act Changes and Correct Errors and Omissions (SNF) | 12009 |
| R4194CP | January 11, 2019 | Update to Publication (Pub.) 100-04 Chapter 25 to Provide Language-Only Changes for the New Medicare Card Project | 11091 |
| R3709CP | February 3, 2017 | Internet Only Manual (IOM) Chapter 25 Revision | 9964 |
| R3435CP | December 31, 2015 | Clarification on Patient's Reason for Visit Necessary to Capture HIPAA Compliant Fields | 9450 |
| R2922CP | April 3, 2014 | Medicare Claims Processing Pub. 100-04 Chapter 25 Update | 8577 |
Sections ordered by the date in the revision note printed under each heading.
| Section | Heading | Revision |
|---|---|---|
| 75.5 | Form Locators43-65 | Rev. 12423, December 20, 2023; effective January 1, 2024 |
| 75.1 | Form Locators 1-15 | Rev. 3709, February 3, 2017; effective April 4, 2017 |
| 75.6 | Form Locators 66-81 | Rev. 3435, December 31, 2015; effective July 1, 2015 |
| 70.1 | Uniform Billing with Form CMS-1450 | Rev. 2922, April 3, 2014; effective April 18, 2014 |
| 70.2 | Disposition of Copies of Completed Forms | Rev. 2922, April 3, 2014; effective April 18, 2014 |
| 75 | General Instructions for Completion of Form CMS-1450 for Billing | Rev. 2922, April 3, 2014; effective April 18, 2014 |
| 75.3 | Form Locators 31-41 | Rev. 2922, April 3, 2014; effective April 18, 2014 |
| 10 | Reserved | Rev. 2874, February 6, 2014; effective March 7, 2014 |
Section index
Every section in the chapter's table of contents, grouped under its top-level heading, with the PDF page where it starts. Open a heading to see its subsections.
10 Reserved · p. 2
70 Uniform Bill - Form CMS-1450 · p. 2 · 2 subsections
- Open section 70 in the PDF
- 70.1 Uniform Billing with Form CMS-1450 · p. 2
- 70.2 Disposition of Copies of Completed Forms · p. 2
75 General Instructions for Completion of Form CMS-1450 for Billing · p. 2 · 6 subsections
- Open section 75 in the PDF
- 75.1 Form Locators 1-15 · p. 10
- 75.2 Form Locators 16-30 · p. 12
- 75.3 Form Locators 31-41 · p. 13
- 75.4 Form Locator 42 · p. 15
- 75.5 Form Locators43-65 · p. 15
- 75.6 Form Locators 66-81 · p. 21
80 Reserved
Using this chapter in a denial or appeal
Start with the remittance. The claim adjustment reason code says what happened to the line, the remark code narrows it, and the group code says who is liable. Match that to the section of the chapter that sets the rule, then read the section in the official PDF rather than a summary: the wording that matters, such as a time limit, a modifier requirement or a documentation element, is usually a single sentence. Check the revision note under the section heading, because a rule that changed after the date of service may not apply to the claim, and an effective date earlier than the issue date can make a new rule reach back.
When the chapter supports the claim, cite it precisely in the redetermination request: the publication number, chapter, section and revision. When it does not, the fix is usually a corrected claim or better documentation rather than an appeal, and a coding or format rejection is corrected and resubmitted because it carries no appeal rights. Manual instructions bind the Medicare Administrative Contractor, so they settle most first-level disputes; at the hearing level, administrative law judges give them substantial deference without being bound by them. If the issue turns on whether a service is covered at all, read the matching Benefit Policy Manual chapter and any national coverage determination or local coverage determination as well, because coverage and billing rules are written in different places.
How QuickIntell works with Claims Processing Manual chapter 25
QuickRCM covers eligibility, claim readiness, denials, posting and A/R with configurable automation and human review, which is where the billing rules in this chapter are checked before a claim goes out. QuickCode supports qualified coder review of the coding and modifier questions the chapter answers.
Frequently asked questions: chapter 25
Is the CMS-1450 the same as the UB-04?
Yes. CMS-1450 is the CMS form number for the institutional claim that the industry calls the UB-04. Chapter 25 of Pub. 100-04 gives Medicare's instructions for each of its form locators.
Which form locator holds the type of bill?
Form locator 4. Chapter 25 section 75.1 explains Medicare's requirements for it together with the other header fields.
Can institutional providers still send paper claims?
Only when they qualify for an exception to the electronic filing requirement. Chapter 24 explains the Administrative Simplification Compliance Act rules; chapter 25 describes the data set either way.
Sources
Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-10. Verify against the primary file before billing or contracting decisions. The reference methodology explains how each figure is computed from these files.
- Medicare Claims Processing Manual, Chapter 25: Completing and Processing the Form CMS-1450 Data SetVersion Rev. 12423, issued 2023-12-20 · effective 2024-01-01 · file clm104c25.pdfSHA-256 0db48c5570eb3b10…
- Medicare Claims Processing Manual (Pub. 100-04)Version 39 chapter PDFs; newest revision Rev. 13836 (chapter 14), issued 2026-06-24 · effective 2026-09-27 · file 100-04-claims-processing-manual/*.pdf (39 chapters; SHA-256 of their sha256sum listing)SHA-256 f87bc3bcd9d1570d…
Disclaimer
This guide summarizes a CMS manual chapter in our own words for billing teams; section headings and transmittal subjects are quoted from the chapter PDF. The chapter itself is the authority, and it changes by transmittal. Not legal, clinical or billing advice.
Found a figure that does not match the CMS file? Report a data correction with the CMS file and the value you expected; the request reaches the editorial team through the contact form.