ICD-10-CM codes
Search the full ICD-10-CM code set
Look up any of the ~97,600 diagnosis codes in the official CMS ICD-10-CM release by code or description — see its chapter, hierarchy, and whether it’s billable.
Try an example: E11.9 (Type 2 diabetes mellitus without complications)
Browse by chapter
All 22 chapters of ICD-10-CM
Every code belongs to exactly one chapter, grouped by body system or condition type — the same structure CMS publishes.
Certain infectious and parasitic diseases
Neoplasms
Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism
Endocrine, nutritional and metabolic diseases
Mental, behavioral and neurodevelopmental disorders
Diseases of the nervous system
Diseases of the eye and adnexa
Diseases of the ear and mastoid process
Diseases of the circulatory system
Diseases of the respiratory system
Diseases of the digestive system
Diseases of the skin and subcutaneous tissue
Diseases of the musculoskeletal system and connective tissue
Diseases of the genitourinary system
Pregnancy, childbirth and the puerperium
Certain conditions originating in the perinatal period
Congenital malformations, deformations and chromosomal abnormalities
Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified
Injury, poisoning and certain other consequences of external causes
External causes of morbidity
Factors influencing health status and contact with health services
Codes for special purposes
For developers
Codes, hierarchy and validity as one API call
Every code page includes its chapter, parent, children and billable status — the same shape returned by the API, so a coding or billing agent can pull the exact same hierarchy it sees on the web page.
- Chapter, category and parent/child hierarchy on every code
patientary api
$ curl patientary.com/api/v1/icd10/E11.9
{
"code": {
"code": "E11.9",
"chapter": "IV",
"billable": true,
"parent": "E11"
}
}FAQ
Common questions about ICD-10 codes
What is an ICD-10 code?
ICD-10-CM (International Classification of Diseases, 10th revision, Clinical Modification) is the code set the US uses to record diagnoses on medical claims and records. Each code identifies a specific condition, from a broad category down to a precise, billable variant. Read the full explainer at /blog/how-icd-10-codes-work.
What's the difference between a billable and a header code?
A billable (leaf) code is specific enough to submit on a claim — e.g. E11.9. A header code is a broader category above it in the hierarchy (e.g. E11) that groups related billable codes but usually can't be billed on its own. Patientary marks every code with a Billable or Header badge.
How many ICD-10-CM codes are there?
The current official CMS ICD-10-CM release has roughly 97,584 codes — about 74,260 billable and 23,324 header codes — organized into 22 chapters by body system or condition type.
Can I search by symptom or condition name instead of a code?
Yes — the search box above matches on code prefix (e.g. "E11") or on the clinical description (e.g. "type 2 diabetes"), so you can search either direction.
Is there an API for ICD-10 lookups?
Yes. GET /api/v1/icd10/{code} returns a single code with its chapter, billable status, parent and children; GET /api/v1/icd10?q= searches by code or description. See /developers.
Patientary is an informational reference tool built on public data (CMS NPPES and the official ICD-10-CM release). It is not medical, coding, legal or billing advice, and code assignment is the responsibility of a qualified professional. Always verify against the primary source before you bill or file.