Yes, RESIDENTS is a Scrabble word!

Letter values in Scrabble US: R 1, E 1, S 1, I 1, D 2, E 1, N 1, T 1, S 1.

Is it a valid word?

RESIDENTS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

someone who lives at a particular place for a prolonged period or who was born there
a physician (especially an intern) who lives in a hospital and cares for hospitalized patients under the supervision of the medical staff of the hospital

Also: house physician, resident physician.