To find an ICD-10 code, type the condition name into a free ICD-10 lookup tool. Enter "diabetes," "hypertension," or any diagnosis keyword and the tool returns the matching codes with full descriptions. The free ICD-10 lookup at EmailAddress.ai searches the full ICD-10-CM code set and is available without a login.
What are ICD-10 codes?
ICD-10 codes are a standardized classification system for diseases, conditions, injuries, and health encounters. The full name is International Classification of Diseases, Tenth Revision. In the United States, providers use ICD-10-CM (Clinical Modification) to report diagnoses on insurance claims, and ICD-10-PCS (Procedure Coding System) for inpatient hospital procedures.
Every claim submitted to Medicare, Medicaid, or a private insurer requires at least one ICD-10-CM diagnosis code. Codes are maintained by the CDC and updated annually on October 1.
How do you find the right ICD-10 code for a diagnosis?
The fastest method is a keyword search:
- Go to the ICD-10 lookup tool.
- Type the condition name or a keyword ("type 2 diabetes," "lower back pain," "pneumonia").
- Review the results. Each result shows the code, the full description, and the chapter it belongs to.
- Select the most specific code that matches the documented diagnosis.
Code to the highest specificity. ICD-10 rewards specificity. "Diabetes mellitus" is not a billable code -- you must specify type 2 (E11), with or without complications, and the specific complication if present. Unspecified codes are accepted but often trigger additional documentation requests from payers.
What is the structure of an ICD-10 code?
ICD-10-CM codes are 3 to 7 characters long. The first character is always a letter. Characters 2 and 3 are numbers. A decimal point separates the category (first 3 characters) from the etiology, anatomic site, severity, and other specifics (characters 4 through 7).
| Position | Meaning | Example |
|---|---|---|
| Character 1 | Chapter (letter) | E = Endocrine diseases |
| Characters 2-3 | Category (number) | E11 = Type 2 diabetes |
| Decimal point | Separator | E11. |
| Characters 4-7 | Specificity | E11.9 = without complications |
What is the difference between ICD-10-CM and ICD-10-PCS?
ICD-10-CM covers diagnosis codes. It is used by all providers -- physicians, hospitals, labs, and therapists -- to document what condition is being treated. It applies to every care setting: inpatient, outpatient, office visits, urgent care.
ICD-10-PCS covers inpatient hospital procedure codes. It is used only by hospitals for facility billing on inpatient stays. Physician procedures in outpatient settings use CPT codes instead.
Most healthcare marketing and data applications involve ICD-10-CM (diagnoses), not ICD-10-PCS.
Common ICD-10 codes and what they look like
| Condition | ICD-10-CM Code | Description |
|---|---|---|
| Type 2 diabetes, uncomplicated | E11.9 | Type 2 diabetes mellitus without complications |
| Essential hypertension | I10 | Essential (primary) hypertension |
| Asthma, unspecified | J45.909 | Unspecified asthma, uncomplicated |
| Major depressive disorder | F32.9 | Major depressive disorder, single episode, unspecified |
| Chronic lower back pain | M54.51 | Vertebrogenic low back pain |
| Atrial fibrillation | I48.91 | Unspecified atrial fibrillation |
| Acute myocardial infarction | I21.9 | Acute myocardial infarction, unspecified |
| COVID-19 | U07.1 | COVID-19 |
How do ICD-10 codes matter for healthcare sales and marketing?
Pharma, biotech, and medical device companies use ICD-10 codes to identify and segment physicians by patient population. A physician whose patients carry frequent diagnoses of I10 (hypertension) or E11 (type 2 diabetes) is a target for relevant treatments and devices.
Claims data, prescribing data, and open payments data are all organized around ICD-10 codes. Sales teams use this to prioritize which physicians to contact and with what message. It is the same logic behind why a cardiologist sees different reps than an endocrinologist -- ICD-10 codes describe each physician's actual patient caseload.
For building physician outreach lists by specialty and patient focus area, the EmailAddress.ai physician database covers 1,993,934 US physicians organized by specialty group and subspecialty, each with a verified work email and NPI match.
Are ICD-10 codes updated every year?
Yes. CMS and the CDC update ICD-10-CM annually, effective October 1. Each fiscal year update adds new codes, revises descriptions, and retires obsolete codes. Claims submitted on or after October 1 must use the current year code set. CMS publishes annual code updates every October 1.
Gautam leads data and growth at EmailAddress.ai. The team has verified over 1.3 billion B2B and healthcare email addresses for pharma, health-tech, and B2B sales teams across 30+ countries.
Search ICD-10 codes free
Look up any diagnosis code by condition name, keyword, or chapter. The full ICD-10-CM code set, searchable in seconds.
Open ICD-10 LookupFrequently asked questions
How do I look up an ICD-10 code by diagnosis name?
Type the condition name or keyword into a free ICD-10 lookup tool. The tool at emailaddress.ai/resources/icd10-lookup searches the full ICD-10-CM code set. Enter "diabetes," "asthma," or any condition name and browse the matching codes and descriptions.
What is the difference between ICD-10-CM and ICD-10-PCS?
ICD-10-CM covers diagnosis codes used by all providers in all care settings. ICD-10-PCS covers inpatient hospital procedure codes. Outpatient and physician procedures use CPT codes, not ICD-10-PCS.
How many ICD-10 codes are there?
ICD-10-CM contains approximately 72,000 codes in the current code set. The number grows each year as new codes are added to accommodate new conditions and greater clinical specificity.
What replaced ICD-9 codes?
ICD-10-CM replaced ICD-9-CM in the United States on October 1, 2015. ICD-10 codes are more specific, longer, and organized differently. Converting old ICD-9 codes to ICD-10 requires a general equivalence mapping (GEM) table -- there is no simple one-to-one replacement for most codes.
Can I use ICD-10 codes to target physicians by patient type?
Yes. Claims and prescribing data tied to ICD-10 codes identify which physicians treat specific conditions. Pharma and device companies use this to segment outreach by therapeutic area. A physician with high diabetes diagnosis volume is a different target than one with predominantly orthopedic diagnoses.
Are ICD-10 codes updated annually?
Yes. Updates take effect every October 1. Always confirm you are using the current fiscal year code set before submitting claims. CMS publishes annual code updates every October 1.