Start with the documented term
Use the FY2027 Alphabetic Index to find a candidate, then confirm that candidate and all applicable instructions in the FY2027 Tabular List. The official FY2027 guidelines, section I.B.1, require both steps. Choose the main term that represents the documented diagnosis or reason for the encounter. Follow the relevant subterms instead of stopping at the first familiar phrase. An Index entry can lead to a category that still needs additional characters.
Search is useful for navigating, but a ranked result is not a code-selection instruction. Open the Alphabetic Index to see the term in context. ICD Code Hub also provides the external-cause index, drug table and neoplasm table.
Follow the index directions
Pay attention to “see” and “see also” references. “See” directs you to another term that must be consulted. “See also” points to another entry that may add useful information; it is not necessary to follow it when the original entry already provides the needed code.
A dash after an index code indicates that more characters are needed. Even without a dash, verify the entry in the Tabular List rather than assuming it is complete.
Verify the code and its parents
Open the full code page, then read the instructions attached to its chapter, block and category as applicable. Inherited instructions can matter even when the individual code has no note of its own. Check the description, laterality, exclusions, sequencing directions and any required seventh character.
For example, M54.5 is a starting point in a hierarchy, while its children provide more detailed entries. Comparing the category and its children shows why a broad search result should not end the lookup.
Make the result easy to review
Keep the chosen code, release and relevant instructions together. The breadcrumb on each Code Hub reference page lets you return to a parent category; the index-term links let you revisit the lookup path. These are useful review steps before a code is copied into another workflow.
If a note is unfamiliar, continue with Excludes1 versus Excludes2. If characters are missing, read the guide to seventh characters and placeholder X.
Common questions
Can I assign a code from the Alphabetic Index alone?
No. The Index directs the lookup; verify the complete entry, parent instructions and specificity in the Tabular List.
What does a dash after an Index code mean?
It indicates that more characters are required. Check the Tabular List to determine the complete code and any applicable instructions.
Where do inherited notes appear?
Notes can sit at a chapter, block or category above the individual code. Review that hierarchy, including relevant exclusions and sequencing directions.
Sources & editorial notes
- FY2027 official guidelines: I.A.5 and I.A.16
- FY2027 official guidelines: I.B.1
- CDC/NCHS: FY2027 official files
- CMS: ICD-10-CM guidelines and files
Educational reference content, prepared with AI assistance; not independently reviewed by a credentialed clinical coding specialist. Verify official instructions and the applicable documentation before assigning codes. Our editorial approach.
Found an error? Send a correction.
