What is the ruling with regards to joining the Imaam in Dua after Salaah?

The Dua made immediately after the Fardh Salaah enjoys a special position in the sense that it is accepted by Allah Ta’ala. When Rasulullah Salallahu Alaihi Wasallam was asked, “Which Dua is more heard (by Allah Ta’ala)?” He replied, “The Dua made in the middle of the night and after the Fardh Salaah.”

Making Dua after the congregational Salaah individually or in congregation is proven from Hadith. However, it should not be regarded as obligatory, thus if any person leaves the congregation before the Dua, then he should not be looked down upon. It is recorded in Fataawa Qaasmiyyah that making Dua after the Fardh Salaah is Mustahab. [Re:- Fataawa Qaasmiyyah Pg.59 Vol.9] In conclusion, a Mustahab act should be afforded the position of a Mustahab. To elevate the position of a Mustahab act is Makrooh. Hence, there is no compulsion is participating in the Dua although doing so will be meritorious.