Basic ICD-10-CM
Chapter 1 Introduction to ICD-10-CM
Characteristics of ICD-10-CM
Used for all diagnosis coding and began on October 1, 2015.
All providers use the code set in the United States health care setting
Divided into the Alphabetic Index, which is an alphabetic listing of terms and codes, and
the Tabular List, which is a numerical list of the codes divided by chapters
Conventions for ICD-10-CM
An understanding of the ICD-10-CM conventions is necessary to assign ICD-10-CM codes
accurately
Address’ structure and format of the coding system, including how to use the Alphabetic
Index and the Tabular List
Alphabetic Index
Alphabetic listing of terms and their corresponding codes
Divided into two parts – the Index to Diseases and Injury and the Index to External
Causes of Injury. Within the Index of Diseases and Injury, there is a Neoplasm Table and
a Table of Drugs and Chemicals
Main Terms
Formatted with main terms set in boldface and listed in alphabetical order.
Main terms are entries printed in boldface type and flush with the left margin of
each column in the Alphabetic Index.
oDiseases such as influenza or bronchitis
oConditions such as fatigue, fracture, or injury
oNouns such as disease, disorder, or syndrome
oAdjectives such as double, kink, or large
Many conditions can be found in more than one place in the Alphabetic Index
Alphabetic Index Subterms
Beneath the main term, any applicable subterms (also called essential modifiers)
will be shown in their own alphabetic list.
Indented subterm is always read in combination with the main term
Forms individual line entries arranged in alphabetical order and printed in regular
type beginning with a lowercase letter
Describe essential differences in the site, cause, or the clinical type of the
condition
More specific subterms are indented farther to the right as needed, indented
one standard indentation after the preceding subterm, and listed in alphabetic
order.
Carryover Lines
Needed on occasion in the Alphabetic Index because the number of words can fit
on a single line of print is limited.
Nonessential Modifiers
A term or a series of terms that appear in parentheses following a main term or
subterm are known as nonessential modifiers.
Presence or absence of these parenthetical terms in the diagnosis statement has
no effect on the selection of the codes listed for the main term or subterm
Not considered descriptors of the diagnosis or condition