How to look up ICD-10-CM codes using the Index and Tabular List

Historical coding exercises: the examples in this lesson use the April–September 2026 release. For services from October 1, 2026, consult the applicable FY2027 release and guidelines on the official CDC/NCHS release page.

A code search can help you locate an entry, but finding a familiar phrase is only the beginning. Reliable learning follows the documented term through the Alphabetic Index, then checks the Tabular List and applicable guidelines.

What you will learn

• Start with documented clinical information
• Follow Index references and verify the Tabular List
• Check full specificity and applicable instructions

Begin with the documented reason for care

Read the documented diagnosis or reason for encounter and identify the appropriate main term in the Alphabetic Index. Follow relevant subterms and mandatory cross-references. A web search for a similar phrase is not an equivalent replacement. If documentation is unclear, seek an authorized clarification rather than diagnosing the patient yourself.

Verify the candidate code

Move from the Index candidate to the Tabular List. Confirm the description, inclusion terms, exclusion notes and instructions at the chapter, category and subcategory levels. Check laterality, required characters and any placeholder. Some entries are headers, not complete reportable codes. The academy’s code reference labels this distinction and displays available inherited tabular notes.

Apply setting and sequencing rules

Review the applicable official guidelines before final assignment. Outpatient and inpatient rules are not interchangeable. A code lookup cannot determine sequencing or clinical relationships without the documentation and guideline context. Record the release used and the reasoning so an instructor can review the process, not just the final code.

Try the workflow step by step

• Underline the documented term in the fictional case; do not add a diagnosis that is not stated or otherwise supported by the applicable coding rules.
• Follow the Index route and cross-references, then inspect the candidate in the Tabular List.
• Record required detail, inherited notes, the release and any unresolved question before discussing final assignment.

A mistake to avoid

Keep a short lookup log. Showing your route and reasoning is more useful for learning than writing only a code number.

Fictional practice exercise

A student finds a matching description in a search result and stops. Write the remaining verification steps without assigning a code.

Worked explanation

Check the Alphabetic Index and its references, verify the full Tabular List entry and higher-level notes, establish specificity, apply setting/sequence guidance and document the release and reasoning.

Can I stop after matching a code description?

No. A description alone does not include every instruction that may affect a code. Higher-level notes, specificity and setting rules can change the analysis.

Roman Urdu recap

Search result starting point hai. Index aur Tabular List dono se code verify hota hai.