ICD-10 CM Conventions and General Coding Guidelines - PART 1

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. 

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

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. 

Punctuation

[ ] 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

 “Unspecified” codes Codes  titled  “unspecified”  are for use when the information in the medical record is insufficient to assign a more specific code.