Final answer:
In the ICD-10-CM code set, the placeholder character used is 'X'. This is employed to maintain the proper code structure and format when necessary, especially for codes requiring lengthier specifications that do not have sufficient information to fill all positions.
Step-by-step explanation:
The ICD-10-CM (International Classification of Diseases, Tenth Revision, Clinical Modification) code set uses various alphanumeric characters to categorize diseases and a wide range of health conditions. A specific feature of this coding system is the utilization of a placeholder character. The role of the placeholder character is to ensure that the code is filled to the correct length and format as required for a particular code category.
In the ICD-10-CM code set, the placeholder character is 'X'. This placeholder is used when a particular code requires a certain length or when more specific data is not available. It is often seen in codes that have optional characters that are not used or when a code requires a 7th character extension, but no available code information fits into the 5th or 6th position. The 'X' serves to hold the place so that the full code maintains the appropriate structure and provides the needed level of specificity.