ICD-10-CM Alphabetic Index · FY 2026 Letter I
Index Terms Starting With I ICD-10-CM
Home › ICD-10-CM Codes List › Index to Diseases and Injuries › IThe letter I section of the FY 2026 Alphabetic Index carries 217 main terms , from I.Q. to Ixodiasis NEC. Terms with a direct code link straight to the code page, cross references point to the main term that holds the codes, and terms with a handful of sub-entries render in full right here. The largest terms open their own full index page.
✓ Built from the official CMS FY 2026 index file Effective Oct 1, 2025 – Sep 30, 2026
All entry types Direct code Cross-references With sub-entries 217 of 217 shown Clear
I.Q. Sub-entries
IBDU (colonic inflammatory bowel dissease unclassified) Code K52.3 ICANS (immune effector cell-associated neurotoxicity syndrome) Cross-ref See: Syndrome, immune effector cell-associated neurotoxicity Ichthyoparasitism due to Vandellia cirrhosa Code B88.8 Ichthyotoxism Sub-entries see Poisoning, fish
bacterial see Intoxication, foodborne
Icteroanemia, hemolytic (acquired) Sub-entries D59.9 congenital see Spherocytosis
Icterus Sub-entries see also Jaundice hematogenous (acquired)
D59.9 Ictus solaris, solis Code T67.01 Non-billable Id reaction (due to bacteria) Code L30.2 Ideation Sub-entries
Identity disorder (child) Sub-entries F64.9 Idiopathic Cross-ref See: condition Idiot, idiocy (congenital) Sub-entries F73 amaurotic (Bielschowsky (-Jansky)) (family) (infantile (late)) (juvenile (late)) (Vogt-Spielmeyer)
E75.4 IIAC (idiopathic infantile arterial calcification) Cross-ref See: Calcification, arterial, generalized, of infancy backwash see Pancolitis, ulcerative (chronic)
regional (ulcerative) see Enteritis, regional, small intestine
segmental see Enteritis, regional
Ileocolitis Sub-entries K52.9 see also Enteritis regional see Enteritis, regional
ulcerative
K51.0 Non-billable Ileostomy Sub-entries
status (ileal pouch) (Kock pouch)
Z93.2 with complication see Complications, enterostomy
Ileotyphus Cross-ref See: Typhoid
Ileum Cross-ref See: condition due to gallstone (in intestine)
K56.3 Iliac Cross-ref See: condition Iliotibial band syndrome Code M76.3 Non-billable Illiteracy Sub-entries Z55.0 Illness Sub-entries R69 see also Disease manic-depressive see Disorder, bipolar
constituents of food intake
E63.1 with
Imbecile, imbecility (I.Q.35-49) Code F71 Imbedding, intrauterine device Code T83.39 Non-billable Imbibition, cholesterol (gallbladder) Code K82.4 Imbrication, teeth,, fully erupted Code M26.30 Imerslund (-Gräsbeck) syndrome Code D51.1 Immature Sub-entries see also Immaturity
birth (less than 37 completed weeks) see Preterm, newborn
extremely (less than 28 completed weeks) see Immaturity, extreme
extreme of newborn (less than 28 completed weeks of gestation) (less than 196 completed days of gestation) (unspecified weeks of gestation)
P07.20 gestational age
23 completed weeks (23 weeks, 0 days through 23 weeks, 6 days)
P07.22 24 completed weeks (24 weeks, 0 days through 24 weeks, 6 days)
P07.23 Immersion Sub-entries T75.1 Non-billable Immobile, immobility Sub-entries
complete, due to severe physical disability or frailty
R53.2 syndrome (paraplegic)
M62.3 Immune reconstitution (inflammatory) syndrome [IRIS] Code D89.3 Immunization Sub-entries see also Vaccination ABO see Incompatibility, ABO
appropriate for age
Immunocompromised NOS Code D84.9 Immunocytoma Code C83.0 Non-billable with
adenosine-deaminase deficiency
D81.30 see also Deficiency, adenosine deaminase Immunodeficient NOS Code D84.9 Immunosuppressed NOS Code D84.9 Immunotherapy (encounter for) Sub-entries
bowel, colon, rectum
K56.49 see also Impaction, fecal calculus see Calculus
cerumen (ear) (external)
H61.2 Non-billable auditory discrimination see Abnormal, auditory perception
cognitive, mild, of uncertain or unknown etiology
G31.84 Impediment, speech Sub-entries R47.9 see also Disorder, speech psychogenic (childhood)
F98.8 Impending Sub-entries
myocardial infarction
I20.0 Imperception auditory (acquired) Sub-entries see also Deafness
aeration, lung (newborn) NEC see Atelectasis
closure (congenital)
alimentary tract NEC
Q45.8 Imperfectly descended testis Cross-ref See: Cryptorchid
Imperforate (congenital) Sub-entries see also Atresia Impervious (congenital) Sub-entries see also Atresia Impetiginization of dermatoses Code L01.1 Impingement (on teeth) Sub-entries
joint see Disorder, joint, specified type NEC
soft tissue
Implant, endometrial Code N80.9 anomalous see Anomaly, by site
cyst
external area or site (skin) NEC
L72.0 Impotence (sexual) Sub-entries N52.9 organic origin
N52.9 see also Dysfunction, sexual, male, erectile Impression, basilar Code Q75.8 Imprisonment, anxiety concerning Code Z65.1 Improper care (child) (newborn) Cross-ref See: Maltreatment Improperly tied umbilical cord (causing hemorrhage) Code P51.8 Impulsiveness (impulsive) Code R45.87 Inability to Sub-entries
comply with dietary regimen
Z91.118 swallow see Aphagia
due to
for admission to facility elsewhere
Z75.1 Inactive Cross-ref See: condition aesthetics of dental restoration
K08.56 biologic, constitutional, functional, or social
F60.7 development
with edema see Malnutrition, severe
due to
deprivation of food
T73.0 Non-billable malnutrition see Malnutrition
change in quantitative human chorionic gonadotropin (hCG) in early pregnancy
O02.81 diet or eating habits
Z72.4 level of quantitative human chorionic gonadotropin (hCG) for gestational age in early pregnancy
O02.81 secretion
Inattention at or after birth Cross-ref See: Neglect Incised wound Sub-entries
external see Laceration
internal organs see Injury, by site
with
gangrene (and obstruction)
K43.1 Inclusion Sub-entries
azurophilic leukocytic
D72.0 blennorrhea (neonatal) (newborn)
P39.1 gallbladder in liver (congenital)
Q44.1 ABO
affecting management of pregnancy
O36.11 Non-billable anti-A sensitization
O36.11 Non-billable anti-B sensitization
O36.19 Non-billable annular
aortic (valve) see Insufficiency, aortic
pulmonary valve (heart)
I37.1 Incomplete Sub-entries see also condition Inconclusive Sub-entries
diagnostic imaging due to excess body fat of patient
R93.9 findings on diagnostic imaging of breast NEC
R92.8 Incontinentia pigmenti Code Q82.3 Incoordinate, incoordination Sub-entries
esophageal-pharyngeal (newborn) see Dysphagia
uterus (action) (contractions) (complicating delivery)
O62.4 abnormal, in development
R63.8 androgens (ovarian)
E28.1 anticoagulants (antithrombin) (anti-VIIIa) (anti-IXa) (anti-Xa) (anti-XIa) see Circulating anticoagulants
Increta placenta Code O43.22 Non-billable Incrustation, cornea, foreign body (lead) (zinc) Cross-ref See: Foreign body, cornea Incyclotropia Cross-ref See: Cyclotropia Indeterminate sex Code Q56.4 India rubber skin Code Q82.8 Indigestion (acid) (bilious) (functional) Sub-entries K30 due to decomposed food NOS
A05.9 Indirect Cross-ref See: condition Induratio penis plastica Code N48.6 Inebriety (without dependence) Cross-ref See: Alcohol, intoxication
Inefficiency, kidney Code N28.9 Inelasticity, skin Code R23.4 Inequality, leg (length) (acquired) Sub-entries see also Deformity, limb, unequal length
congenital see Defect, reduction, lower limb
lower leg see Deformity, limb, unequal length
bladder (neurogenic)
N31.2 uterus, uterine during labor
O62.2 genitalia, genitals (after puberty)
E30.0 Herter's (nontropical sprue)
K90.0 Infant (s) Sub-entries see also Infancy lack of care see Neglect
liveborn (singleton)
Z38.2 Infantile Sub-entries see also condition genitalia, genitals
E30.0 Infantilism Cross-ref See: Infancy
adrenal (capsule) (gland)
E27.49 appendices epiploicae
K55.069 see also Infarct, intestine bowel
K55.069 see also Infarct, intestine brain (stem) see Infarct, cerebral
Infecting Cross-ref See: condition with
drug resistant organism see also specific organism Resistance (to), drug
lymphangitis see Lymphangitis
organ dysfunction (acute)
R65.20 Infective, infectious Cross-ref See: condition Acanthocheilonema (perstans) (streptocerca)
B74.4 amyloid (generalized) (localized) see Amyloidosis
localized see Degeneration, by site
Infirmity Sub-entries R68.89 abducent (nerve) see Strabismus, paralytic, sixth nerve
accessory sinus (chronic) see Sinusitis
Inflation, lung, imperfect (newborn) Cross-ref See: Atelectasis
with
digestive manifestations
J11.2 Influenzal Cross-ref See: Influenza
Influenza-like disease Cross-ref See: Influenza
Infraction, Freiberg's (metatarsal head) Cross-ref See: Osteochondrosis, juvenile, metatarsus Infraeruption of tooth (teeth) Code M26.34 Infusion complication, misadventure, or reaction Cross-ref See: Complications, infusion
chemical see Table of Drugs and Chemicals, by substance, poisoning
drug or medicament
correct substance properly administered see Table of Drugs and Chemicals, by drug, adverse effect
overdose or wrong substance given or taken see Table of Drugs and Chemicals, by drug, poisoning
Ingrowing Sub-entries
nail (finger) (toe)
L60.0 Inguinal Sub-entries see also condition
major neurocognitive disorder
F18.97 mild neurocognitive disorder
F18.988 food or foreign body see Foreign body, by site
gases, fumes, or vapors
T59.9 Non-billable Inhibition, orgasm Sub-entries
Inhibitor, systemic lupus erythematosus (presence of) Code D68.62 Iniencephalus, iniencephaly Code Q00.2 Injection, traumatic jet (air) (industrial) (water) (paint or dye) Code T70.4 Non-billable Injury Sub-entries T14.90 Non-billable see also specified injury type abdomen, abdominal
S39.91 Non-billable blood vessel see Injury, blood vessel, abdomen
cavity see Injury, intra-abdominal
Inoculation Sub-entries see also Vaccination
complication or reaction see Complications, vaccination
Insanity, insane Sub-entries see also Psychosis adolescent see Schizophrenia
Insect Sub-entries
bite see Bite, by site, superficial, insect
venomous, poisoning NEC (by) see Venom, arthropod
Insecurity Sub-entries
Insensitivity Sub-entries
adrenocorticotropin hormone (ACTH)
E27.49 Insertion Sub-entries
cord (umbilical) lateral or velamentous
O43.12 Non-billable intrauterine contraceptive device (encounter for) see Intrauterine contraceptive device
Insolation (sunstroke) Code T67.01 Non-billable Inspiration Sub-entries
food or foreign body see Foreign body, by site
mucus see Asphyxia, mucus
Inspissated bile syndrome (newborn) Code P59.1 emotional (excessive)
F60.3 housing
Institutional syndrome (childhood) Code F94.2 Institutionalization, affecting child Sub-entries Z62.22 disinhibited attachment
F94.2 accommodation, old age
H52.4 Insufflation, fallopian Code Z31.41 Insular Cross-ref See: condition Insuloma Cross-ref See: Insulinoma Interference Sub-entries
Intermenstrual Cross-ref See: condition Intermittent Cross-ref See: condition Internal Cross-ref See: condition cardiac defibrillator (automatic) (implantable)
Z45.02 cardiac (event) (loop) recorder
Z45.09 infusion pump (implanted) (intrathecal)
Z45.1 Interruption Sub-entries
phase-shift, sleep cycle see Disorder, sleep, circadian rhythm
sleep phase-shift, or 24 hour sleep-wake cycle see Disorder, sleep, circadian rhythm
Interstitial Cross-ref See: condition Intertrigo Sub-entries L30.4 Intervertebral disc Cross-ref See: condition Intestine, intestinal Cross-ref See: condition disaccharide, hereditary
E73.0 Intoxicated NEC (without dependence) Cross-ref See: Alcohol, intoxication
alcoholic (acute) (without dependence) see Alcohol, intoxication
amphetamine (without dependence) see also Abuse, drug, stimulant, with intoxication
Intraabdominal testis, testes Sub-entries
Intracranial Cross-ref See: condition Intrahepatic gallbladder Code Q44.1 Intraligamentous Cross-ref See: condition Intrathoracic Sub-entries see also condition
immediately following removal
Z30.433 Intraventricular Cross-ref See: condition Intrinsic deformity Cross-ref See: Deformity Intubation, difficult or failed Code T88.4 Non-billable Intumescence, lens (eye) (cataract) Cross-ref See: Cataract
Intussusception (bowel) (colon) (enteric) (ileocecal) (ileocolic) (intestine) ( rectum) Sub-entries K56.1 ureter (with obstruction)
N13.5 Invagination (bowel, colon, intestine or rectum) Code K56.1 albumin-globulin (A-G) ratio
E88.09 cecum see Intussusception
Investigation Sub-entries Z04.9 see also Examination clinical research subject (control) (normal comparison) (participant)
Z00.6 Involuntary movement, abnormal Code R25.9 Involution, involutional Sub-entries see also condition breast, cystic see Dysplasia, mammary, specified type NEC
depression (single episode)
F32.89 melancholia (single episode)
F32.89 IRDS (type I) Sub-entries P22.0 Iridis rubeosis Cross-ref See: Disorder, iris, vascular
Iridochoroiditis (panuveitis) Cross-ref See: Panuveitis
Iridocyclochoroiditis (panuveitis) Cross-ref See: Panuveitis
Iridodialysis Code H21.53 Non-billable Iridoplegia (complete) (partial) (reflex) Code H57.09 Iridoschisis Code H21.25 Non-billable Iris Sub-entries see also condition
bombé see Membrane, pupillary
Iritis Sub-entries see also Iridocyclitis chronic see Iridocyclitis, chronic
diabetic see E08-E13 with .39
due to
Iron Cross-ref See: condition Iron-miner's lung Code J63.4 Irradiated enamel (tooth, teeth) Code K03.89 Irradiation effects, adverse Code T66 Non-billable Irreducible, irreducibility Cross-ref See: condition brain see Ischemia, cerebral
bowel (transient)
acute
K55.059 see also Ischemia, intestine, acute Ischial spine Cross-ref See: condition Ischialgia Cross-ref See: Sciatica
Ischium, ischial Cross-ref See: condition Iselin's disease or osteochondrosis Cross-ref See: Osteochondrosis, juvenile, metatarsus parotid tissue in
submaxillary glands in
Islet cell tumor, pancreas Code D13.7 Isoimmunization NEC Sub-entries see also Incompatibility affecting management of pregnancy (ABO) (with hydrops fetalis)
O36.11 Non-billable anti-A sensitization
O36.11 Non-billable anti-B sensitization
O36.19 Non-billable anti-c sensitization
O36.09 Non-billable Isolation, isolated Sub-entries
Isomerism atrial appendages (with asplenia or polysplenia) Code Q20.6 Isosporiasis, isosporosis Code A07.3 Isovaleric acidemia Code E71.110 Issue of Sub-entries
for disability determination
Z02.71 repeat prescription (appliance) (glasses) (medicinal substance, medicament, medicine)
Z76.0 contraception see Contraception
IST (inappropriate sinus tachycardia, so stated) Code I47.11 Itch, itching Sub-entries see also Pruritus Ivemark's syndrome (asplenia with congenital heart disease) Code Q89.01 Related References Source: Centers for Medicare & Medicaid Services, FY 2026 ICD-10-CM Index to Diseases and Injuries release files, effective October 1, 2025 through September 30, 2026.
