Navigating ICD-10 Codes
ICD-10-CM includes an official Index, official Conventions, and official Guidelines. These are designed to help medical coders find and assign the correct diagnosis codes for their patients’ conditions.
Instructions and Conventions
The ICD-10 code set includes Section I Conventions, general coding guidelines applicable to the overall classification, and chapter-specific guidelines. Sections II – IV Conventions outline rules and principles for the selection of primary diagnoses, reporting additional diagnoses, and diagnostic coding and reporting of outpatient services.
Additionally, the Official Guidelines for Coding and Reporting, based on sequencing instructions in the Tabular List and Alphabetic Index of ICD-10-CM, provide further assistance for correct ICD-10 coding.
Alphabetic Index
This four-part index encompasses the Index of Diseases and Injury, the Index of External Causes of Injury, the Table of Neoplasms, and the Table of Drugs and Chemicals, all of which are designed to streamline the process of locating the necessary diagnosis codes and ICD-10 coding instructions.
Index to Diseases and Injuries
Arranged alphabetically across hundreds of pages, this index list diseases, injuries, and diagnostic terms, along with their associated codes (or code categories). Sub-lists of related or more-detailed terms with their corresponding codes appear beneath many of the main terms.
Table of Neoplasms
This table enables you to locate codes for neoplasms by anatomical site and then quickly narrow your selection by cross-referencing the anatomical location with six traits, depending on whether the diagnosis is malignant primary, malignant secondary, Ca in situ, benign, of uncertain behavior, or of unspecified behavior.
(The neoplasm diagnosis codes are laid out in table format to condense the index, which would consume reams of pages if laid out in list format.)
Neoplasm |
Malignant Primary |
Malignant Secondary |
Carcinoma in situ |
Benign |
Uncertain Behavior |
Unspecified Behavior |
Neoplasm, neoplastic |
C80.1 |
C79.9 |
D09.9 |
D36.9 |
D48.9 |
D49.9 |
abdomen, abdominal |
C76.2 |
C79.8- |
D09.8 |
D36.7 |
D48.7 |
D49.89 |
cavity |
C76.2 |
C79.8- |
D09.8 |
D36.7 |
D48.7 |
D49.89 |
organ |
C76.2 |
C79.8- |
D09.8 |
D36.7 |
D48.7 |
D49.89 |
viscera |
C76.2 |
C79.8- |
D09.8 |
D36.7 |
D48.7 |
D49.89 |
wall (see also Neoplasm, abdomen, wall, skin) |
C44.509 |
C79.2- |
D04.5 |
D23.5 |
D48.5 |
D49.2 |
connective tissue |
C49.4 |
C79.8- |
- |
D21.4 |
D48.1 |
D49.2 |
Table of Drugs and Chemicals
Similar to the Table of Neoplasms, the Table of Drugs and Chemicals allows you to locate codes for poisoning or allergic reactions by cross-referencing the responsible substance with six circumstances that specify whether the substance-related condition was accidental, intentional self-harm, assault, undetermined, adverse effect, or the result of underdosing.
Index of External Causes of Injury
ICD-10 external cause codes provide details explaining the events surrounding an injury, which are especially useful in collecting statistics for policy decisions concerning public health. These ICD-10 codes also play an important role in workers’ compensation claims.
The Index of External Causes of Injury is arranged similar to the Index to Diseases and Injuries, listing entries and sub-entries in alphabetical order along with their corresponding codes.
Tabular List
The Tabular List refers to the actual listing of ICD-10 codes and their descriptors. You’ll also find instructions that will help you apply the codes correctly, as well as lists of additional diagnoses that a code applies to, sequencing rules, or which diagnoses codes are excluded from an ICD-10 code.
The Tabular List is organized into 21 chapters according to body system or condition, with diagnosis codes listed alphanumerically in each chapter.
ICD-10-CM Chapters and Code Ranges
Chapter
|
Code Range
|
Description
|
1
|
A00-B99
|
Certain Infectious and Parasitic Diseases
|
2
|
C00-D49
|
Neoplasms
|
3
|
D50-D89
|
Diseases of the Blood and Blood-Forming Organs and Certain Disorders Involving the Immune Mechanism
|
4
|
E00-E89
|
Endocrine, Nutritional and Metabolic Diseases
|
5
|
F01-F99
|
Mental, Behavioral and Neurodevelopmental Disorders
|
6
|
G00-G99
|
Diseases of the Nervous System
|
7
|
H00-H59
|
Diseases of the Eye and Adnexa
|
8
|
H60-H95
|
Diseases of the Ear and Mastoid Process
|
9
|
I00-I99
|
Diseases of the Circulatory System
|
10
|
J00-J99
|
Diseases of the Respiratory System
|
11
|
K00-K95
|
Diseases of the Digestive System
|
12
|
L00-L99
|
Diseases of the Skin and Subcutaneous Tissue
|
13
|
M00-M99
|
Diseases of the Musculoskeletal System and Connective Tissue
|
14
|
N00-N99
|
Diseases of the Genitourinary System
|
15
|
O00-O9A
|
Pregnancy, Childbirth and the Puerperium
|
16
|
P00-P96
|
Certain Conditions Originating in the Perinatal Period
|
17
|
Q00-Q99
|
Congenital Malformations, Deformations, and Chromosomal Abnormalities
|
18
|
R00-R99
|
Symptoms, Signs, and Abnormal Clinical and Laboratory Findings, Not Elsewhere Classified
|
19
|
S00-T88
|
Injury, Poisoning, and Certain Other Consequences of External Causes
|
20
|
V00-Y99
|
External Causes of Morbidity
|
21
|
Z00-Z99
|
Factors Influencing Health Status and Contact with Health Services
|