Is it permissible to perform Salatul-Istikhara in the middle of university studies for a major that was not previously prayed for through Istikhara?

It is permissible to perform Istikhara (prayer for guidance) regarding continuing in an academic specialization or changing it. This is done by specifying the matter in the Istikhara supplication, for Istikhara can be performed for continuing an action just as it can be performed for initiating one, and also for abandoning or rescinding an action, provided the choice rests with the individual. Istikhara is not performed for obligations (Wajibat) and recommended acts (Mustahabbat) (concerning their performance), nor for forbidden acts (Muharramat) and disliked acts (Makruhat) (concerning their abandonment). Rather, it is confined to permissible acts (Mubah) and recommended acts when two matters conflict. This includes continuing an action or abandoning it, as mentioned in the Hadith of Jabir ibn Abdullah regarding the Prophet's (peace be upon him) teaching of Istikhara in "all matters."