My son recently moved into a house built in 1957 that has an updated panel with ground connected to the bus bar. However, the receptacles I've checked are old two-pronged receptacles in metal boxes fed by 14/2 Romex cable. Unfortunately, I haven't found any outlets yet that are serviced by armored cable.

I believe that NEC code requires these outlets be GFCI protected to comply with current code. Is this correct?

I've checked other questions and can't find a specific answer to this question.