Guides ICD-10 update cycle
How Often Are ICD-10 Codes Updated?
Both ICD-10-CM and ICD-10-PCS are republished once a year and take effect on October 1, the first day of the federal fiscal year. Between releases the code set does not move, which is what makes a fixed annual date workable.
Once a year, effective October 1
Both ICD-10 code sets used in the United States follow the same rhythm: one release per year, effective October 1.
- ICD-10-CM — diagnosis codes, published by CDC/NCHS with CMS. Annual, effective October 1.
- ICD-10-PCS — inpatient procedure codes, published by CMS. Annual, effective October 1.
They share the date but not the content: each has its own file, its own additions and its own deletions. A year with heavy ICD-10-CM activity may be a quiet one for ICD-10-PCS, and the two change lists have to be read separately.
Between releases the code set is stable. A code's description does not quietly change in February; if something is different, it is because a new release took effect.
Why releases are named by fiscal year
October 1 is the first day of the United States federal fiscal year, so a release effective October 1, 2026 belongs to fiscal year 2027 — a release named for a year that has not started yet in calendar terms. This trips people up constantly.
| Release | Effective | Status here |
|---|---|---|
| FY 2026 | October 1, 2025 | Superseded |
| FY 2027 | October 1, 2026 | Current |
How a change gets into a release
New codes do not appear by administrative fiat. CMS and NCHS jointly run the ICD-10 Coordination and Maintenance Committee, which holds public meetings where proposals for new, revised or deleted codes are presented and discussed. Proposals can come from clinicians, specialty societies, researchers, industry and the public. NCHS handles the diagnosis side; CMS handles the procedure side.
After a proposal is heard, comments are taken, and the decisions that survive the process are incorporated into the next release. When the release is published, it is accompanied by addenda that state exactly what changed relative to the prior year — which is the document trail that makes an independent comparison possible in the first place.
The maintenance process also allows for off-cycle updates where a new technology needs a code before the next October. Those are the exception; the October 1 release is the one to plan around.
What a release contains
A release restates the entire code set, not just the differences. Comparing it against the prior release classifies each code as:
| Change | Meaning |
|---|---|
| New | Present in the new release, absent from the prior one. |
| Revised | Present in both, with a changed description or a changed validity flag. |
| Deleted | Present in the prior release, absent from the new one. |
| Unchanged | Present in both, identical. The great majority of codes, every year. |
MedCodeSearch computes these comparisons from the release files themselves rather than transcribing a summary, so the counts on the update pages are reproducible from the sources. The exact figures for each release are on Code Updates — for the current year, ICD-10-CM FY 2027 and ICD-10-PCS FY 2027, each broken out into new, revised and deleted lists.
What is current right now
The current release of both ICD-10 code sets is FY 2027, effective October 1, 2026. Every code page on this site states which release it is showing and when that release took effect, so there is never a question of which year's wording you are reading. Data Sources lists exactly what has been imported.
What the cycle means in practice
- A date determines which code set applies. Records and encounters are coded against the release in effect at the time, so an older record can legitimately carry a code that no longer exists.
- Deleted codes stay relevant. They remain in historical data, in analyses, and in anything that looks back across years. See What Happens When a Medical Code Is Deleted?
- Revisions can be subtle. A description edit does not change a code's identity, but it can change how the code reads. A code's page here lists one entry per release it has appeared in, so a wording change is visible rather than silently overwritten.
- HCPCS runs on a different clock. HCPCS Level II updates quarterly, not annually — see How Often Are HCPCS Codes Updated?
Official sources
Where the facts on this page come from. MedCodeSearch is an independent reference service; these organizations publish the code sets themselves.
- CDC / NCHS — ICD-10-CM release files
The official ICD-10-CM files, organized by fiscal year. This is the directory MedCodeSearch imports from.
- CMS — ICD-10 codes
CMS publishes the ICD-10-PCS files and the annual ICD-10 update materials.
- CDC — National Center for Health Statistics
NCHS is responsible for the U.S. clinical modification of the ICD diagnosis classification.
Look up a code
Search every current ICD-10-CM, ICD-10-PCS and HCPCS Level II code, or browse a set from the top of its hierarchy.
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This guide explains how the code sets are built and published. It is not coding, billing, legal or medical advice, and it never recommends a code for a specific patient or claim. See the Disclaimer and Methodology pages.