Gather all ingredients.

Pour cold water and lemon juice into a multi-functional pressure cooker (such as Instant Pot). Place a steamer rack inside; coat with cooking spray.

Place frozen salmon fillets, skin-side down, on the prepared rack. Cover and close the vent.

Cook on the Steam setting until fish flakes easily with a fork, 3 to 4 minutes. Release pressure carefully using the quick-release method according to manufacturer's instructions, about 5 minutes. Unlock and remove the lid.