For FHA, answers can be found in the 4000.1 handbook. I would say yes, deck and stairs need railing.
page 1094 FHA handbook states : The Mortgagee must repair damaged or missing handrails or stair treads on elevated exterior porches, patios, decks, and balconies where the distance from the finished floor to the ground surface is greater than 18 inches. If repair is not feasible, the Mortgagee must provide temporary rails, fencing, or other means to prevent or mitigate falls.