ICD-10-CM QUICK REFERENCE GUIDE
Since 1979, in the United States the reporting of diagnoses has been done using Volumes 1 and 2 of the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD9-CM). For encounters and discharges on and after October 1, 2014, the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) will be implemented in
the United States.
CHAPTERS (code ranges)
Chapter 1: Certain Infectious and Parasitic Diseases (A00 – B99)
Chapter 2: Neoplasms (C00 – D49)
Chapter 3: Diseases of the Blood and Blood-forming Organs and Certain Disorders Involving the Immune Mechanism (D50 - D89)
Chapter 4: Endocrine, Nutritional, and Metabolic Diseases (E00 – E89)
Chapter 5: Mental, Behavioral and Neurodevelopmental Disorders (F01 – F99)
Chapter 6: Diseases of the Nervous System (G00 – G99)
Chapter 7: Diseases of the Eye and Adnexa (H00 – H59)
Chapter 8: Diseases of Ear and Mastoid Process (H60 – H95)
Chapter 9: Diseases of the Circulatory System (I00 – I99)
Chapter 10: Diseases of the Respiratory System (J00 – J99)
Chapter 11: Diseases of the Digestive System (K00 – K95)
Chapter 12: Diseases of Skin and Subcutaneous Tissue (L00 – L99)
Chapter 13: Diseases of the Musculoskeletal System and Connective Tissue (M00 – M99)
Chapter 14: Diseases of the Genitourinary System (N00 – N99)
Chapter 15: Pregnancy, Childbirth, and the Puerperium (O00 – O9A)
Chapter 16: Certain Conditions Originating in the Perinatal Period (P00 – P96)
Chapter 17: Congenital Malformations, Deformations and Chromosomal Abnormalities (Q00 – Q99)
Chapter 18: Symptoms, Signs and Abnormal Clinical and Laboratory Findings, Not Elsewhere Classified (R00 – R99)
Chapter 19: Injury, Poisoning and Certain Other Consequences of External Causes (S00 – T88)
Chapter 20: External Causes of Morbidity (V00 – Y99)
Chapter 21: Factors Influencing Health Status and Contact with Health Services (Z00 – Z99)

CODE STRUCTURE
3 to 7 characters, for example:
I10 Essential (primary hypertension)
R65.21 - Severe sepsis with septic shock
•
K21.0 - Gastro-esophageal reflux disease with esophagitis
E10.641 - Type 1 diabetes mellitus with hypoglycemia with coma
•
•

Use of decimal after character 3

Character 7 is used in certain chapters to provide information about the characteristics of the encounter, for example:
- the stage of glaucoma (chapter 7)
- gout complications (chapter 13)
- initial, subsequent, or complication-related encounter (chapters 13, 19, 20)
- the specific fetus of a multiple gestation (chapter 15) - coma scoring time/location (chapter 18)
- fracture type/clinical status (chapter 19)

Character 7 reporting frequently requires that a dummy placeholder “x” be reported as well. The “x” has two uses:
- fills out an empty character space when a code contains fewer than 6 characters and a 7 th character applies
- provides for future expansion without disturbing the sixth character structure.

The following is an excerpt from the ICD-10-CM tabular list. T68 is not a valid code, the appropriate 7th character and dummy placeholder “x” are
needed to assign valid code T68.xxxA, T68.xxxD or T68.xxxS:
Character 1 is alpha (all letters used except “U”)
Character 2 is numeric
Characters 3 – 7 are alpha or numeric
T68
Hypothermia - The appropriate 7th character is to be added to code T68
A - initial encounter
D - subsequent encounter
S – sequela

Alpha characters are not case sensitive, they may be lower case or capitalized, for example:
Essential (primary hypertension) - I10 or i10
Gastro-esophageal reflux disease with esophagitis K21.0 or k21.0
Severe sepsis with septic shock - R65.21 or r65.21
Type 1 diabetes mellitus with hypoglycemia with coma - E10.641 or e10.641

Laterality (side of the body) has been added to relevant codes, for example:
C56.1 Malignant neoplasm of right ovary
C56.2 Malignant neoplasm of left ovary
ICD-10-CM QUICK REFERENCE GUIDE
ICD-10-CM Diagnosis Coding Example for a Patient Diagnosed with “Acute Bleeding Stomach Ulcer”
ICD-10-CM Index Excerpt:
ICD-10-CM Tabular List Excerpt:
Ulcer, ulcerated, ulcerating, ulceration, ulcerative
- stomach (eroded) (peptic) (round) K25.9
- - with
- - - hemorrhage K25.4
- - - - and perforation K25.6
- - - perforation K25.5
- - acute K25.3
- - - with
- - - - hemorrhage K25.0 Tentative code
- - - - - and perforation K25.2
- - - - perforation K25.1
- - chronic K25.7
- - - with
- - - - hemorrhage K25.4
- - - - - and perforation K25.6
- - - - perforation K25.5
K25
Gastric ulcer
Includes: erosion (acute) of stomach
pylorus ulcer (peptic)
stomach ulcer (peptic)
Use additional code to identify:
alcohol abuse and dependence (F10.-)
Excludes1:
K25.0
K25.1
K25.2
K25.3
K25.4
K25.5
K25.6
K25.7
K25.9
acute gastritis (K29.0-)
peptic ulcer NOS (K27.-)
Acute gastric ulcer with hemorrhage Final code
Acute gastric ulcer with perforation
Acute gastric ulcer with both hemorrhage and perforation
Acute gastric ulcer without hemorrhage or perforation
Chronic or unspecified gastric ulcer with hemorrhage
Chronic or unspecified gastric ulcer with perforation
Chronic or unspecified gastric ulcer with both hemorrhage
and perforation
Chronic gastric ulcer without hemorrhage or perforation
Gastric ulcer, unspecified as acute or chronic, without
hemorrhage or perforation
ICD-10 RESOURCES:
The CMS ICD-10 website http://www.cms.gov/icd10 provides the latest ICD-10 information and links to resources for providers to prepare for ICD-10 implementation.
The CMS Sponsored ICD-10 Teleconferences web page at http://www.cms.gov/ICD10/Tel10/list.asp provides information on upcoming and previous CMS ICD-10
National Provider Calls, including registration, presentation materials, video slideshow presentations, podcasts, written transcripts and audio recordings
Medicare Fee-for-Service Provider Resources are available at
http://www.cms.gov/ICD10/06_MedicareFeeforServiceProviderResources.asp
Provider Resources (for all providers) http://www.cms.gov/ICD10/05a_ProviderResources.asp (this web page
provides links to a variety of related educational resources and information)
The following organizations also provide ICD-10 resources:

WEDI (Workgroup for Electronic Data Interchange) http://www.wedi.org

HIMSS (Health Information and Management Systems Society) http://www.himss.org/icd10
Lolita M. Jones Consulting Services * www.EZMedEd.com * July 2012