- Internal - see condition
- Interproximal wear 521.10
- Interruption
- Intersexuality 752.7
- Interstitial - see condition
- Intertrigo 695.89
- Intervertebral disc - see condition
- Intestine, intestinal - see also condition
- Intolerance
- Intoxicated NEC (see also Alcoholism) 305.0
- Intoxication
- Intracranial - see condition
- Intrahepatic gallbladder 751.69
- Intraligamentous - see also condition
- Intraocular - see also condition
- Intrathoracic - see also condition
- Intrauterine contraceptive device
- Intraventricular - see condition
- Intrinsic deformity - see Deformity
- Intruded tooth 524.34
- Intrusion, repetitive, of sleep (due to environmental disturbances) (with atypical polysomnographic features) 307.48
- Intumescent, lens (eye) NEC 366.9
