The official coding guidelines, free to download and free of an email wall. Most of these are U.S. federal government works and therefore public domain — we mirror those here so the link never rots, and we always point you at the publisher's original so you can verify our copy. WHO material is linked rather than mirrored.
The full official guidelines effective October 1, 2025 through September 30, 2026 — Section I conventions and chapter-specific rules, Section II and III inpatient selection, and Section IV outpatient rules.
U.S. federal government work — public domain
The official addenda: every code added, deleted, or revised for FY 2026, plus the tabular and index change lists. Distributed by NCHS as a ZIP archive.
U.S. federal government work — public domain
The codes exempt from present-on-admission reporting — the list inpatient coders check before assigning a POA indicator.
U.S. federal government work — public domain
The procedure-coding guidelines effective October 1, 2025 — the A/B/C conventions, body-system and root-operation rules, and the multiple-procedure guidance that drives most PCS denials.
U.S. federal government work — public domain
WHO's full reference guide to ICD-11 — how the MMS linearization, stem codes, extension codes and post-coordination clusters actually fit together. Published as a browsable web document.
WHO, CC BY-ND 3.0 IGO — linked, not mirrored
The authoritative WHO coding tool for the current ICD-11 release. Use it to confirm a stem code or work out a post-coordination cluster.
WHO, CC BY-ND 3.0 IGO — linked, not mirrored
The last ICD-9-CM guidelines NCHS published, effective October 1, 2011 and left in place through the ICD-10 transition. Kept here for historical research, audits of legacy claims, and crosswalk work.
U.S. federal government work — public domain
Medical Coding Hub is not affiliated with, and these documents are not endorsed by, NCHS, CMS, or the World Health Organization. See Data Sources & Attribution for the full provenance of everything on this site.