Where our data comes from, who published it, and what we owe them.
Medical Coding Hub is built almost entirely on work that other people funded, wrote, and gave away — federal statisticians at NCHS and CMS, WHO’s classification committees, and volunteer encyclopedists. We are grateful for it, and we name it precisely, so you can always check what you read here against the original.
National Center for Health Statistics (NCHS) & Centers for Medicare & Medicaid Services (CMS), U.S. Department of Health and Human Services
Tabular list, alphabetic index, neoplasm and drug tables, inclusion terms, Excludes1/Excludes2 notes, and annual addenda.
ICD-10-CM is published by NCHS and CMS. ICD-10-CM is the United States clinical modification of the World Health Organization’s ICD-10, developed by NCHS under authorization from WHO.
Centers for Medicare & Medicaid Services (CMS)
Inpatient procedure code set, code tables, and annual updates.
ICD-10-PCS is developed and published by CMS.
Centers for Medicare & Medicaid Services (CMS)
HCPCS Level II alphanumeric codes and descriptors, quarterly and annual releases.
HCPCS Level II is maintained and published by CMS.
HCPCS Level I is CPT®, copyright American Medical Association. We do not host, mirror, or reproduce CPT® codes or descriptors anywhere on this site.
NCHS & CMS
The final ICD-9-CM code set (v32, FY2015 — diagnoses and Volume 3 procedures) with its tabular chapter/section hierarchy, plus the 2018 General Equivalence Mappings that power every ICD-9 ↔ ICD-10 crosswalk on the site.
ICD-9-CM and the GEMs are published by NCHS and CMS.
Centers for Medicare & Medicaid Services (CMS)
Medicare Severity Diagnosis Related Groups from the ICD-10 MS-DRG Definitions Manual v43.1, with relative weights and mean lengths of stay from Table 5 of the FY 2026 IPPS final rule.
MS-DRGs and the IPPS payment tables are published by CMS.
World Health Organization (WHO)
The full ICD-11 MMS linearization (2026-01 release) — chapters, blocks and categories with WHO’s codes and titles reproduced verbatim — plus WHO’s published ICD-10 ↔ ICD-11 mapping tables.
ICD-11 is copyright © World Health Organization, licensed under CC BY-ND 3.0 IGO. Codes and titles are reproduced without adaptation.
The ICD-11 license permits commercial use but prohibits adaptations of the classification. We reproduce, we do not modify.
Centers for Medicare & Medicaid Services (CMS)
Annual national utilization counts and average allowed amounts, used to compute the estimated-spend figures shown on code and chapter pages.
Underlying figures are from CMS public use files. Estimated annual spend shown on this site is our own calculation derived from that data — it is not a CMS-published figure.
NCHS and CMS (mirrored); World Health Organization (linked only)
The official guidelines PDFs offered for download on /ebooks and on each code set page: ICD-10-CM FY 2026, ICD-10-PCS FY 2026, and the final ICD-9-CM edition (effective October 1, 2011).
We host these files only because they are U.S. federal government works and therefore public domain. Every mirrored file links back to the publisher’s original so you can verify our copy, and states its publisher, fiscal year, and licence.
WHO ICD-11 material is licensed CC BY-ND 3.0 IGO. The ICD-11 Reference Guide and MMS browser are linked, never mirrored, so there is no question of adaptation.
Medical Coding Hub
The coding briefings on code pages, generated by large language models and grounded in the official metadata above.
Reports are labelled either “AI Flash Briefing — one-shot draft” or “Verified Full Report.” Neither is official guidance, and neither replaces the Official Guidelines or professional judgment.
Planned integrations. Listed here in advance so our attribution commitments are on the record before the content ships.
CMS and NCHS, approved by the four Cooperating Parties: American Hospital Association, American Health Information Management Association, CMS, and NCHS
The official coding and sequencing rules, to be reproduced in full and linked to the chapters, categories, and codes they govern.
The Official Guidelines are published by CMS and NCHS. We will reproduce them verbatim, cite the fiscal year and effective dates, and link the source PDF on every page that renders them.
AHA Coding Clinic is copyright American Hospital Association. We may cite it by issue; we do not reproduce it.
Wikipedia contributors; Wikimedia Foundation
Plain-language clinical background for conditions, matched to codes through Wikidata identifiers rather than text matching.
Excerpts will be reproduced verbatim and credited to the named article and its authors, linked to the exact revision used, with the CC BY-SA 4.0 license linked alongside. Wikidata structured data is CC0; we credit it regardless.
Wikipedia images are licensed individually and are not covered by an article’s text license. They are out of scope until each file’s license is resolved.
No endorsement.Nothing on this site implies endorsement by the Centers for Disease Control and Prevention, the National Center for Health Statistics, the Centers for Medicare & Medicaid Services, the U.S. Department of Health and Human Services, the World Health Organization, the Wikimedia Foundation, or the United States Government.
Not medical, coding, legal, or billing advice.This site is a reference aid. It does not replace the official publications, your organization’s policies, or professional judgment. For authoritative text, always consult the primary sources linked above.
Think we’ve credited something incorrectly, or missed a source? Tell us and we will fix it.
Last reviewed: July 2026.