ICD-10-CM (International Classification of Diseases, 10th Revision, Clinical Modification) is the standardized coding system used in the United States for reporting medical diagnoses on healthcare claims. It contains over 70,000 codes organized into 21 chapters based on body systems and condition types.

How many chapters are in ICD-10-CM?

ICD-10-CM is organized into 21 chapters. Each chapter covers a specific body system or type of condition, ranging from infectious diseases (Chapter 1) to factors influencing health status (Chapter 21). Code ranges span from A00 through Z99.

How often is ICD-10-CM updated?

ICD-10-CM is updated annually by CMS (Centers for Medicare & Medicaid Services). Updates take effect on October 1st of each fiscal year and include new codes, revised codes, and deleted codes to reflect advances in medical knowledge and practice.

What are the most commonly used ICD-10 codes?

Some of the most frequently used ICD-10 codes include E11.9 (Type 2 diabetes without complications), I10 (Essential hypertension), J06.9 (Acute upper respiratory infection), M54.5 (Low back pain), Z23 (Encounter for immunization), and F32.9 (Major depressive disorder).

How do I find the correct ICD-10 code?

To find the correct ICD-10 code, first identify the main diagnosis or condition. Search the alphabetic index by condition name, then verify in the tabular list. Always code to the highest level of specificity available and follow the official ICD-10-CM coding guidelines for proper code selection and sequencing.

ICD-10-CM Code Directory

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ICD-10-CM is organized into 21 chapters based on body system or condition type

Chapter 1 A00-B99

Certain Infectious and Parasitic Diseases

Bacterial, viral, fungal, and parasitic infections

Chapter 2 C00-D49

Neoplasms

Malignant, benign, and uncertain behavior neoplasms

Chapter 3 D50-D89

Blood and Blood-Forming Organs

Anemias, coagulation defects, immune disorders

Chapter 4 E00-E89

Endocrine, Nutritional and Metabolic Diseases

Diabetes, thyroid disorders, obesity, malnutrition

Chapter 5 F01-F99

Mental, Behavioral and Neurodevelopmental Disorders

Depression, anxiety, substance use, dementia

Chapter 6 G00-G99

Diseases of the Nervous System

Parkinson's, epilepsy, neuropathies, migraines

Chapter 7 H00-H59

Diseases of the Eye and Adnexa

Cataracts, glaucoma, retinal disorders, vision issues

Chapter 8 H60-H95

Diseases of the Ear and Mastoid Process

Hearing loss, otitis, vestibular disorders

Chapter 9 I00-I99

Diseases of the Circulatory System

Heart failure, hypertension, stroke, arrhythmias

Chapter 10 J00-J99

Diseases of the Respiratory System

COPD, asthma, pneumonia, respiratory failure

Chapter 11 K00-K95

Diseases of the Digestive System

GERD, liver disease, GI bleeding, hernias

Chapter 12 L00-L99

Diseases of the Skin and Subcutaneous Tissue

Dermatitis, psoriasis, cellulitis, pressure ulcers

Chapter 13 M00-M99

Diseases of the Musculoskeletal System

Arthritis, osteoporosis, back pain, fractures

Chapter 14 N00-N99

Diseases of the Genitourinary System

Chronic kidney disease, UTIs, renal failure

Chapter 15 O00-O9A

Pregnancy, Childbirth and the Puerperium

Pregnancy complications, delivery, postpartum care

Chapter 16 P00-P96

Certain Conditions Originating in the Perinatal Period

Birth trauma, prematurity, neonatal conditions

Chapter 17 Q00-Q99

Congenital Malformations and Chromosomal Abnormalities

Birth defects, genetic disorders

Chapter 18 R00-R99

Symptoms, Signs and Abnormal Clinical Findings

Signs, symptoms, abnormal lab results

Chapter 19 S00-T88

Injury, Poisoning and Certain Other Consequences of External Causes

Fractures, burns, poisoning, adverse effects

Chapter 20 V00-Y99

External Causes of Morbidity

Accidents, assaults, self-harm, complications

Chapter 21 Z00-Z99

Factors Influencing Health Status and Contact with Health Services

Screenings, history codes, status codes, encounters

Commonly Used ICD-10 Codes

102 frequently used diagnosis codes organized by ICD-10-CM chapter

Chapter 1: Certain Infectious and Parasitic Diseases (A00-B99)

A41.9

Sepsis, unspecified organism

Chapter 2: Neoplasms (C00-D49)

C34.90

Malignant neoplasm of unspecified part of unspecified bronchus or lung

C61

Malignant neoplasm of prostate

Chapter 3: Blood and Blood-Forming Organs (D50-D89)

D50.9

Iron deficiency anemia, unspecified

D64.9

Anemia, unspecified

D69.6

Thrombocytopenia, unspecified

D72.829

Elevated white blood cell count, unspecified

Chapter 4: Endocrine, Nutritional and Metabolic Diseases (E00-E89)

E03.9

Hypothyroidism, unspecified

E11.9

Type 2 diabetes mellitus without complications

E55.9

Vitamin D deficiency, unspecified

E78.00

Pure hypercholesterolemia, unspecified

E78.5

Hyperlipidemia, unspecified

E86.0

Dehydration

E87.1

Hypo-osmolality and hyponatremia

E87.5

Hyperkalemia

E87.6

Hypokalemia

Chapter 5: Mental, Behavioral and Neurodevelopmental Disorders (F01-F99)

F03.90

Unspecified dementia without behavioral disturbance

F41.1

Generalized anxiety disorder

F41.9

Anxiety disorder, unspecified

Chapter 6: Diseases of the Nervous System (G00-G99)

G20.A1

Parkinson's disease without dyskinesia, without mention of fluctuations

G40.909

Epilepsy, unspecified, not intractable, without status epilepticus

G45.9

Transient cerebral ischemic attack, unspecified

G62.9

Polyneuropathy, unspecified

G89.29

Other chronic pain

G89.4

Chronic pain syndrome

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Chapter 9: Diseases of the Circulatory System (I00-I99)

I10

Essential (primary) hypertension

I21.4

Non-ST elevation (NSTEMI) myocardial infarction

I25.10

Atherosclerotic heart disease of native coronary artery without angina pectoris

I26.99

Other pulmonary embolism without acute cor pulmonale

I48.91

Unspecified atrial fibrillation

I50.9

Heart failure, unspecified

I51.9

Heart disease, unspecified

I63.9

Cerebral infarction, unspecified

I73.9

Peripheral vascular disease, unspecified

I82.409

Acute embolism and thrombosis of unspecified deep veins of lower extremity

I95.9

Hypotension, unspecified

Chapter 10: Diseases of the Respiratory System (J00-J99)

J02.9

Acute pharyngitis, unspecified

J18.9

Pneumonia, unspecified organism

J30.9

Allergic rhinitis, unspecified

J32.9

Chronic sinusitis, unspecified

J40

Bronchitis, not specified as acute or chronic

J44.1

Chronic obstructive pulmonary disease with acute exacerbation

J44.9

Chronic obstructive pulmonary disease, unspecified

J90

Pleural effusion, not elsewhere classified

J96.90

Respiratory failure, unspecified, unspecified whether with hypoxia or hypercapnia

Chapter 11: Diseases of the Digestive System (K00-K95)

K21.9

Gastro-esophageal reflux disease without esophagitis

K56.609

Unspecified intestinal obstruction, unspecified as to partial versus complete

K57.90

Diverticulosis of intestine, part unspecified, without perforation or abscess without bleeding

K57.92

Diverticulitis of intestine, part unspecified, without perforation or abscess without bleeding

Chapter 12: Diseases of the Skin and Subcutaneous Tissue (L00-L99)

L03.90

Cellulitis, unspecified

Chapter 13: Diseases of the Musculoskeletal System (M00-M99)

M19.90

Unspecified osteoarthritis, unspecified site

M25.511

Pain in right shoulder

M25.512

Pain in left shoulder

M25.519

Pain in unspecified shoulder

M25.561

Pain in right knee

M25.562

Pain in left knee

M25.569

Pain in unspecified knee

M54.12

Radiculopathy, cervical region

M54.16

Radiculopathy, lumbar region

M54.17

Radiculopathy, lumbosacral region

M54.2

Cervicalgia

M54.50

Low back pain, unspecified

M54.9

Dorsalgia, unspecified

M81.0

Age-related osteoporosis without current pathological fracture

M85.80

Other specified disorders of bone density and structure, unspecified site

M86.9

Osteomyelitis, unspecified

Chapter 14: Diseases of the Genitourinary System (N00-N99)

N10

Acute pyelonephritis

N12

Tubulo-interstitial nephritis, not specified as acute or chronic

N17.9

Acute kidney failure, unspecified

N18.9

Chronic kidney disease, unspecified

N20.0

Calculus of kidney

N30.90

Cystitis, unspecified without hematuria

N39.0

Urinary tract infection, site not specified

N39.498

Other specified urinary incontinence

N40.0

Benign prostatic hyperplasia without lower urinary tract symptoms

Chapter 18: Symptoms, Signs and Abnormal Clinical Findings (R00-R99)

R00.0

Tachycardia, unspecified

R05.9

Cough, unspecified

R06.02

Shortness of breath

R06.81

Apnea, not elsewhere classified

R07.89

Other chest pain

R07.9

Chest pain, unspecified

R09.02

Hypoxemia

R10.2

Pelvic and perineal pain

R10.9

Unspecified abdominal pain

R11.0

Nausea

R13.10

Dysphagia, unspecified

R19.7

Diarrhea, unspecified

R30.0

Dysuria

R31.9

Hematuria, unspecified

R32

Unspecified urinary incontinence

R33.9

Retention of urine, unspecified

R35.0

Frequency of micturition

R42

Dizziness and giddiness

R50.9

Fever, unspecified

R51.9

Headache, unspecified

R53.1

Weakness

R53.83

Other fatigue

R55

Syncope and collapse

R56.9

Unspecified convulsions

R73.03

Prediabetes

R74.01

Elevation of liver transaminase levels

R91.1

Solitary pulmonary nodule

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ICD-10-CM Code Directory

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Browse by ICD-10-CM Chapter

Certain Infectious and Parasitic Diseases

Neoplasms

Blood and Blood-Forming Organs

Endocrine, Nutritional and Metabolic Diseases

Mental, Behavioral and Neurodevelopmental Disorders

Diseases of the Nervous System

Diseases of the Eye and Adnexa

Diseases of the Ear and Mastoid Process

Diseases of the Circulatory System

Diseases of the Respiratory System

Diseases of the Digestive System

Diseases of the Skin and Subcutaneous Tissue

Diseases of the Musculoskeletal System

Diseases of the Genitourinary System

Pregnancy, Childbirth and the Puerperium

Certain Conditions Originating in the Perinatal Period

Congenital Malformations and Chromosomal Abnormalities

Symptoms, Signs and Abnormal Clinical Findings

Injury, Poisoning and Certain Other Consequences of External Causes

External Causes of Morbidity

Factors Influencing Health Status and Contact with Health Services

Commonly Used ICD-10 Codes

Chapter 1: Certain Infectious and Parasitic Diseases (A00-B99)

Chapter 2: Neoplasms (C00-D49)

Chapter 3: Blood and Blood-Forming Organs (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)

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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 the Skin and Subcutaneous Tissue (L00-L99)

Chapter 13: Diseases of the Musculoskeletal System (M00-M99)

Chapter 14: Diseases of the Genitourinary System (N00-N99)

Chapter 18: Symptoms, Signs and Abnormal Clinical Findings (R00-R99)

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