To clarify, the circuit is almost always 20A with 15A being used for lighting. However, the outlet itself is almost always 15A because you put multiple outlets

To clarify, the circuit is almost always 20A with 15A being used for lighting. However, the outlet itself is almost always 15A because you put multiple outlets on a single circuit. You are going to see very few 20A in outlets (which have a T shaped prong) in residential.