What is the ruling on praying while seated due to medical reasons, given that one may experience occasional forgetfulness?

The objective of standing while praying is that a person perform it while fully aware of their actions and words. Accordingly, if a legally accountable person is physically able to stand during prayer but cannot remain fully attentive to what they are doing and saying, or retain sufficient awareness of their actions and words except when praying while seated, then they are regarded in Islamic law as one who is unable to stand. They therefore come under the ruling mentioned in the hadith of ‘Umran ibn Hasin, who narrated that the Prophet (peace and blessings be upon him) said, “Pray while standing; and if you cannot, then while seated; and if you cannot, then while lying on your side” (recorded by Bukhari).

Based on the above, it is permissible for a person to pray while seated if standing during prayer causes them to lose focus or awareness in the prayer.

And Allah Almighty knows best.