The T20 category is for athletes with intellectual impairment.

T20 athletes have an IQ score of 75 or less.

The Athletics at the 2016 Summer Paralympics – Men's 400 metres T20 event at the 2016 Paralympic Games took place on 8–9 September 2016, at the Estádio Olímpico João Havelange.

18:13 8 September 2016:[1] 18:21 8 September 2016:[1] 11:20 9 September 2016:[2]