Peel the potatoes and quarter them. Add the potatoes to the Instant pot and pour in water just to cover them (approximately 3 cups), then add 1 tsp salt.
Pressure cook for 8 minutes, then quick release the pressure and drain the potatoes. Let them steam dry for a couple of minutes before mashing.
Mash with the cream cheese, hot milk and butter until no lumps left. Taste and season with salt. My preferred tool for mashing is a potato masher or a potato ricer for the smoothest mash.