Free Tool

ICD-10-CM Code Lookup

Search 70,000+ ICD-10-CM diagnosis codes instantly. Type a keyword (e.g. diabetes) or a code (e.g. E11) to get started.

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Try: diabetes hypertension J18 (pneumonia) fracture Z23 (immunization)
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Results for "J18"

6 codes found

✕ Clear Search
Code Description Billable Category
J18 Pneumonia, unspecified organism Header Respiratory System
J180 Bronchopneumonia, unspecified organism ✔ Yes Respiratory System
J181 Lobar pneumonia, unspecified organism ✔ Yes Respiratory System
J182 Hypostatic pneumonia, unspecified organism ✔ Yes Respiratory System
J188 Other pneumonia, unspecified organism ✔ Yes Respiratory System
J189 Pneumonia, unspecified organism ✔ Yes Respiratory System
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How to Use This ICD-10-CM Lookup Tool

This free tool lets you search the complete ICD-10-CM code set used in the United States. You can search two ways:

  • By keyword — type a condition name like diabetes, hypertension, or pneumonia to see all matching codes
  • By code prefix — type a code like E11 to see all codes in that category

Understanding the Results

  • Billable (✔ Yes) — this code can be used on a claim. It's specific enough to submit.
  • Header — this is a category-level code. You must use a more specific child code for billing.
  • Category — the ICD-10-CM chapter this code belongs to (e.g. Endocrine, Respiratory).
📋 CPC Exam Tip — ICD-10-CM Sequencing On the CPC exam, always sequence the principal diagnosis first. For combination codes (a single code that captures two conditions), use the combination code rather than two separate codes. Check the Tabular List for "Use additional code" and "Code first" instructions.

Official ICD-10-CM Resources

This tool is for educational use. For official billing and compliance purposes, always verify codes against:

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How to Use an ICD-10-CM Code Lookup Correctly

A code search tool is a fast way to find a code. It is not a substitute for coding, and treating it as one is how coders build habits that cost them marks on the exam and denials in the real world. This page explains how to use a lookup properly and where it must stop.

The Rule That Governs Every ICD-10-CM Lookup

Never assign a code from the Alphabetic Index alone. The Index points you toward a code; the Tabular List confirms it. This rule exists because the Tabular List contains information the Index simply does not carry: additional character requirements, Excludes1 and Excludes2 notes, "code first" and "use additional code" instructions, and laterality or encounter detail.

The same rule applies to any search tool, including this one. Search to find the neighbourhood. Open your ICD-10-CM manual to confirm the exact code.

Searching by Keyword

Searching by Code Prefix

Entering the first three characters shows you a whole category at once, which is often more useful than a keyword search. Browsing the category reveals sibling codes you did not know existed, and shows you immediately whether the category needs a fourth, fifth, sixth or seventh character.

ICD-10-CM codes run from three to seven characters. A three-character code is only valid if it has no further subdivision. If a category expands, the three-character code alone is not billable — this is one of the most common errors in beginner coding.

What a Search Tool Cannot Do For You

TaskToolManual / guidelines
Find candidate codes fastYesSlower
Confirm character requirementsPartlyYes
Show Excludes1 / Excludes2 notesNoYes
Apply sequencing rulesNoYes
Decide principal vs secondary diagnosisNoYes
Judge whether documentation supports the codeNoYes — plus clinical judgement

Sequencing Is Where Codes Become Coding

Finding the right codes is only half the job. Which one goes first is frequently the point of an exam question. Underlying conditions and their manifestations follow instructional notes in the Tabular List. Obstetric, injury and poisoning chapters each carry their own sequencing rules. A perfectly accurate set of codes in the wrong order is still a wrong answer.

Practising With This Tool

A productive drill: take a short clinical scenario, decide the codes from your book first, then use the search to check yourself. Doing it in that order builds coding skill. Doing it in the reverse order builds dependence on a search box that will not be in the exam room with you.

Source and Accuracy

ICD-10-CM is maintained by the Centers for Medicare & Medicaid Services and the National Center for Health Statistics, and the code set is updated annually, with changes effective 1 October. Always verify against the current official code set and the current ICD-10-CM Official Guidelines for Coding and Reporting before applying a code to a live claim.