Format and Structure
The Tabular List contains are Categories Subcategories codes.
All categories are 3 characters. A three-character category that has no further subdivision. The Subcategories are either 4 or 5 characters. The Codes maybe 3, 4, 5, 6, or 7 characters. That is, each level of subdivision after a category is a subcategory. The final level of subdivision is a code.
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
NEC - Not Elsewhere Classifiable
NEC - This abbreviation in the Alphabetic Index & Tabular List represents “other specified.” When a specific code is not available for a condition, the Alphabetic Index directs the coder to the “other specified” code in the Tabular List.
NOS - Not Otherwise Specified
NOS - This abbreviation is the equivalent of unspecified.
[ ] Brackets are used in the Tabular List to enclose synonyms, alternative wording, or explanatory phrases. Brackets are used in the Alphabetic Index to identify manifestation codes.
( ) Parentheses are used in both the Alphabetic Index and Tabular List to enclose supplementary words that may be present or absent in the statement of a disease or procedure without affecting the code number to which it is assigned. The terms within the parentheses are referred to as nonessential modifiers.
: Colons are used in the Tabular List after an incomplete term which needs one or more of the modifiers following the colon to make it assignable to a given category.
Other Specified Codes
“Other” codes Codes titled “other” or “other specified” are for use when the information in the medical record provides detail for which a specific code does not exist in the alphabetic index or Tabular list
“Unspecified” codes Codes titled “unspecified” are for use when the information in the medical record is insufficient to assign a more specific code.