There are 13 words that start with 'postt'.
| posttax | postteen |
| posttest | postteens |
| posttests | posttrial |
| posttension | posttensions |
| posttensioned | posttraumatic |
| posttreatment | posttensioning |
| posttransfusion | |
Note: These 13 words that start with 'postt' are found from the USA & Canada version of the tournament Scrabble word list.