Placeholder character

The ICD-10-CM utilizes a placeholder character “X”. The “X” is used as a placeholder at certain codes to allow for future expansion. An example of this is at the poisoning, adverse effect and underdosing codes, categories T36-T50. Where a placeholder exists, the X must be used in order for the code to be considered a valid code. 5. 7th Characters Certain ICD-10-CM categories have applicable 7th characters.

The applicable 7th character is required for all codes within the category, or as the notes in the Tabular List instruct. The 7th character must always be the 7th character in the data field. If a code that requires a 7th character is not 6 characters, a placeholder X must be used to fill in the empty characters.