TL;DR
Chapter 26 of the Medicare Claims Processing Manual explains how professional claims are completed on Form CMS-1500 and its electronic equivalent. It gives Medicare's item-by-item instructions for patient, insured and provider information, holds the official list of place of service codes and their definitions, and explains type of service, specialty codes and the miles, times, units and services field.
Chapter 26 at a glance
- Current revision
- Rev. 12779
- Issued August 9, 2024
- Effective
- August 1, 2024
- Implemented January 6, 2025
- Sections
- 16
- 3 top-level sections
- Transmittals in history
- 99
- Listed at the end of the chapter
- Monthly searches
- 70
- Google Ads, US, October 2026
What chapter 26 governs for billing
Medicare requires electronic claims unless a supplier qualifies for an exception under the Administrative Simplification Compliance Act, so the paper form matters mostly as the map of the data a professional claim must carry. Section 10 walks through the form. Items 1 to 13 hold the beneficiary and insured information, including the Medicare Beneficiary Identifier and the information needed to decide whether another insurer pays first (10.2 and 10.3). Items 14 to 33 hold the provider and service information (10.4): the referring or ordering practitioner and that practitioner's NPI in item 17, up to twelve ICD-10-CM diagnosis codes in item 21, the service lines in item 24 with dates, place of service, HCPCS codes with up to four modifiers, diagnosis pointers, charges and units, the service facility in item 32 and the billing provider and NPI in item 33.
Section 10.5 is the reason many people look this chapter up: it is CMS's list of place of service codes with their definitions. The place of service drives the site-of-service differential under the Physician Fee Schedule, so the same service is paid at the facility rate when billed with an inpatient or outpatient hospital code and at the higher non-facility rate in an office. The chapter's own example is that a physician seeing a registered hospital outpatient uses an outpatient hospital code, on campus or off campus, and not the office code. Section 10.6 adds Medicare's instructions for applying the codes.
The remaining sections cover type of service codes that contractors assign (10.7), the physician and supplier specialty codes used on enrollment and claims (10.8), and the miles, times, units and services indicator that tells the system whether the units field counts miles, minutes or services (10.9). Sections 20 and 30 cover the beneficiary's own request for payment form and the printing specifications for the CMS-1500.
Sections billing teams use most
Section numbers and headings are CMS's; the notes are ours. Each section number opens the official chapter 26 PDF at the page where that section starts.
| Section | CMS heading | Why it matters |
|---|---|---|
| 10.2 | Items 1-11 - Patient and Insured Information | Items 1 to 11: beneficiary, insured and other-insurance information that decides who pays first. |
| 10.4 | Items 14-33 - Provider of Service or Supplier Information | Items 14 to 33: referring provider, diagnoses, service lines, facility and billing provider. |
| 10.5 | Place of Service Codes (POS) and Definitions | The official place of service code list and definitions, updated as CMS adds codes. |
| 10.6 | A/B Medicare Administrative Contractor (MAC) (B) Instructions for Place of Service (POS) Codes | Medicare instructions for choosing place of service on professional claims. |
| 10.8 | Requirements for Specialty Codes | Physician and supplier specialty codes used in enrollment and claims processing. |
| 10.9 | Miles/Times/Units/Services (MTUS) | Miles, times, units and services: how the units field is read for each service type. |
How chapter 26 shows up on claims and denials
Errors in the CMS-1500 data set usually make a claim unprocessable rather than denied. Missing or invalid items come back with reason code 16 and a remark code that names the field, for example M77 for a missing or invalid place of service or N290 for a missing rendering provider identifier. An unprocessable claim has no appeal rights; it is corrected and resubmitted.
Place of service errors are also payment errors. A procedure code that is inconsistent with the place of service is denied with reason code 5, and billing the office code for a hospital outpatient overstates payment because the non-facility rate is higher. Auditors look for exactly this mismatch, so the place of service should match where the beneficiary actually received the service.
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 | Claim lacks information or has a billing error; a remark code names the field. |
| M77 | Remark code | Missing, incomplete or invalid place of service. |
| N290 | Remark code | Missing or invalid rendering provider identifier. |
| 5 | Claim adjustment reason code | Procedure code inconsistent with the place of service. |
| 58 | Claim adjustment reason code | Service rendered in an inappropriate or invalid place of service. |
Current revision and recent transmittals
The chapter PDF posted on cms.gov is current through Rev. 12779, issued August 9, 2024, effective August 1, 2024, implemented January 6, 2025 (change request 13749). That revision changed section 10.5 (Place of Service Codes (POS) and Definitions). Its subject line reads: “New Place of Service (POS) Code 66 - "Programs of All-Inclusive Care for the Elderly (PACE) Center"”.
The newest rows of the transmittal history printed at the end of the chapter (99 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 |
|---|---|---|---|
| R12779CP | August 9, 2024 | New Place of Service (POS) Code 66 - "Programs of All-Inclusive Care for the Elderly (PACE) Center" | 13749 |
| R12671CP | June 6, 2024 | Billing and Payment for Telehealth Services with Place of Service (POS) 10 | 13582 |
| R12456CP | January 11, 2024 | New Physician Specialty Code for Epileptologists | 13425 |
| R12411CP | December 14, 2023 | New Place of Service (POS) Code 27 - "Outreach Site/Street" | 13314 |
| R12231CP | August 31, 2023 | New Dental Specialty Codes for Medicare | 13323 |
| R11437CP | May 27, 2022 | New/Modifications to the Place of Service (POS) Codes for Telehealth | 12427 |
Sections ordered by the date in the revision note printed under each heading.
| Section | Heading | Revision |
|---|---|---|
| 10.5 | Place of Service Codes (POS) and Definitions | Rev. 12779, August 9, 2024; effective August 1, 2024 |
| 10.8.2 | Physician Specialty Codes | Rev. 12456, January 11, 2024; effective July 1, 2024 |
| 10.4 | Items 14-33 - Provider of Service or Supplier Information | Rev. 10341, September 4, 2020; effective October 6, 2020 |
| 10.8.3 | Nonphysician Practitioner, Supplier, and Provider Specialty Codes | Rev. 10124, May 8, 2020; effective October 1, 2020 |
| 20 | Patient's Request for Medical Payment Form CMS-1490S | Rev. 4388, September 6, 2019; effective October 7, 2019 |
| 10.2 | Items 1-11 - Patient and Insured Information | Rev. 4232, February 8, 2019; effective March 12, 2019 |
| 10.6 | A/B Medicare Administrative Contractor (MAC) (B) Instructions for Place of Service (POS) Codes | Rev. 3490, April 1, 2016; effective April 25, 2016 |
| 10 | Health Insurance Claim Form CMS-1500 | Rev. 3083, October 2, 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 Health Insurance Claim Form CMS-1500 · p. 2 · 13 subsections
- Open section 10 in the PDF
- 10.1 Claims That Are Incomplete or Contain Invalid Information · p. 4
- 10.2 Items 1-11 - Patient and Insured Information · p. 4
- 10.3 Items 11a - 13 - Patient and Insured Information · p. 7
- 10.4 Items 14-33 - Provider of Service or Supplier Information · p. 9
- 10.5 Place of Service Codes (POS) and Definitions · p. 20
- 10.6 A/B Medicare Administrative Contractor (MAC) (B) Instructions for Place of Service (POS) Codes · p. 36
- 10.7 Type of Service (TOS) · p. 38
- 10.8 Requirements for Specialty Codes · p. 40
- 10.8.1 Assigning Specialty Codes by A/B MACs (B) and DME MACs
- 10.8.2 Physician Specialty Codes · p. 41
- 10.8.3 Nonphysician Practitioner, Supplier, and Provider Specialty Codes · p. 43
- 10.9 Miles/Times/Units/Services (MTUS) · p. 45
- 10.9.1 Methodology for Coding Number of Services, MTUS Count and MTUS Indicator Fields · p. 46
20 Patient's Request for Medical Payment Form CMS-1490S · p. 48
30 Printing Standards and Print File Specifications Form CMS-1500 · p. 50
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 26
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 26
Where is the official list of place of service codes?
Chapter 26 of the Medicare Claims Processing Manual, section 10.5, lists each place of service code with its name and definition. CMS updates it by transmittal when it adds or changes codes, and the current revision is shown at the top of this page.
Which POS code should a physician use for a hospital outpatient?
Chapter 26 says that when the patient is a registered hospital outpatient, the physician uses the on-campus or off-campus outpatient hospital code, and for a registered inpatient the inpatient hospital code, not the office code.
How many diagnosis codes fit on a CMS-1500?
The 02/12 version of the form takes up to twelve ICD-10-CM diagnosis codes in item 21, and each service line points to the diagnoses that support it in item 24E.
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 26: Completing and Processing Form CMS-1500 Data SetVersion Rev. 12779, issued 2024-08-09 · effective 2024-08-01 · file clm104c26.pdfSHA-256 4fae39895fea412a…
- 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.