- Insurance examination (certification) V70.3
- Intemperance (see also Alcoholism) 303.9
- Interception of pregnancy (menstrual extraction) V25.3
- Interference
- Intermenstrual
- Intermittent - see condition
- Internal - see condition
- Interproximal wear 521.10
- Interrogation
- 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
