ICD-10 Code Lookup
Search the full FY2026 ICD-10-CM code set — all 74,000+ diagnosis codes — by condition or code number. Official descriptions, instant results, free.
The right code, before the claim goes out.
Coding to the highest available specificity is what keeps a claim from being denied for an unspecified or invalid diagnosis — but looking every code up by hand is slow and error-prone. CodeSightTM reads the clinical note and suggests the ICD-10 & CPT codes for you, with a human-review queue for anything uncertain.
How to read an ICD-10 code
Every code is 3 to 7 characters. Take E11.65 (type 2 diabetes with hyperglycemia) — here's what each part is doing:
E11 The core diagnosis: type 2 diabetes mellitus. Always a letter followed by two characters..65 Adds specificity after the decimal: here, “with hyperglycemia.” Up to four more characters describe the cause, body site, or severity.Some codes add two more things: laterality (right vs. left — common on injuries) and a 7th character for the encounter type — A initial, D subsequent, S sequela. A code has to be its full length to be billable. For example, S52.521A = fracture of the shaft of the right radius, initial encounter.
The in-depth guides below walk through the common condition families — the right code, common mistakes, and what the note has to document.
ICD-10 coding guides by condition
Full guides for the highest-volume condition families — the right code, common mistakes, and what the note has to document.
A brief history of ICD
The International Classification of Diseases has organized the world's diagnoses for more than 130 years — here's how it got from a list of causes of death to the 74,000-code set you search today.
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1893
The Bertillon ClassificationThe first international disease list — prepared by French statistician Jacques Bertillon and adopted by the International Statistical Institute — gave countries a common way to record causes of death.1
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1948
The WHO takes over (ICD-6)With its sixth revision, the World Health Organization became the custodian of the ICD and expanded it beyond mortality to cover non-fatal illness — the start of ICD as a clinical tool, not just a death register.1
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2015
The US adopts ICD-10-CMOn October 1, 2015, US healthcare switched from ICD-9-CM (about 14,000 codes) to ICD-10-CM (over 70,000) — a roughly five-fold jump in specificity. The US was one of the last countries to make the move.2
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2022
ICD-11 goes live worldwideThe WHO's fully digital 11th revision took effect on January 1, 2022. US clinical and billing systems still run on ICD-10-CM, so ICD-11 is not yet used for coding in the United States.3
Today, ICD-10-CM (diagnoses) is maintained by the CDC's National Center for Health Statistics, and ICD-10-PCS (inpatient procedures) by CMS, with updates each October.4
- World Health Organization. History and development of the International Classification of Diseases (ICD).
- American Medical Association. It's official: ICD-10 compliance date now Oct. 1, 2015.
- Pan American Health Organization / WHO. WHO's new International Classification of Diseases (ICD-11) comes into effect (2022).
- CDC / National Center for Health Statistics. International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM).
Frequently Asked Questions
Yes. ICD-10-CM codes and their official descriptions are published in the public domain by CMS and the CDC's National Center for Health Statistics — free to look up and use. (This differs from CPT codes, which are copyrighted by the American Medical Association.) Medmio's lookup tool and coding guides are free for reference.
The FY2026 ICD-10-CM code set contains about 74,000 billable diagnosis codes. It is maintained by CMS and the CDC and updated each year effective October 1, with a mid-year update effective April 1.
ICD-10-CM (Clinical Modification) codes describe diagnoses and are used in every care setting. ICD-10-PCS (Procedure Coding System) codes describe inpatient hospital procedures only. This tool covers ICD-10-CM diagnosis codes.
ICD-10-CM is updated annually, effective October 1 (the start of the federal fiscal year), with a smaller mid-year update effective April 1. Codes are added, revised, and deactivated. Always confirm a code's active status against the current fiscal-year release for the date of service.
Yes. The tool runs entirely in your browser. The code set is downloaded once and all searching happens on your own device — nothing you type is uploaded, stored, or sent to any server.
Yes. Medmio's CodeSightTM engine reads the clinical note and suggests the ICD-10-CM and CPT codes, with a human-review queue for anything low-confidence — so coding is faster and more consistent than manual lookup. This free lookup tool is a reference companion.
US healthcare adopted ICD-10-CM (diagnoses) and ICD-10-PCS (inpatient procedures) on October 1, 2015, replacing ICD-9-CM. The change expanded the diagnosis code set from roughly 14,000 codes to over 70,000, for far greater specificity.
Not yet. The WHO's ICD-11 took effect internationally on January 1, 2022, but US clinical documentation and billing still use ICD-10-CM. There is no confirmed US transition date to ICD-11 for coding.