Alphabetic Index

A code listed next to a main term in the ICD-10-CM Alphabetic Index is referred to as a default code, which:

• Is the condition most commonly associated with the main term or
• Shows that it's the unspecified code for the condition

Assign a default code if a condition is documented in a medical record without any additional information, like acute or chronic.

In the Alphabetic Index example to the right, the default code for Lumbago, lumbalgia is M54.50.

Lumbago, lumbalgia M54.50
- with sciatica M54.4-
- - due to intervertebral disc disorder M51.17
- due to displacement, intervertebral disc M51.27
- - with sciatica M51.17