- Taussig-Bing defect, heart, or syndrome (transposition, aorta and overriding pulmonary artery) 745.11
- Tay's choroiditis 363.41
- Tay-Sachs
- Taybi's syndrome (otopalatodigital) 759.89
- Taylor's
- TBI (traumatic brain injury) (see also Injury, intracranial) 854.0
- Tear stone 375.57
- Tear, torn (traumatic) - see also Wound, open, by site
- Teeth, tooth - see also condition
- Teething 520.7
- Tegmental syndrome 344.89
- Telangiectasia, telangiectasis (verrucous) 448.9
- Telecanthus (congenital) 743.63
- Telescoped bowel or intestine (see also Intussusception) 560.0
- Teletherapy, adverse effect NEC 990
- Telogen effluvium 704.02
- Temper tantrum (childhood) (see also Disturbance, conduct) 312.1
- Temperature
- Temple - see condition
- Temporal - see also condition
- Temporomandibular joint-pain-dysfunction syndrome 524.60
- Temporosphenoidal - see condition