If the overflow is puking with conviction and the rad cap is in good repair, meaning gasket is good and spring is solid, yes, it is overheating.
However, normal operation is some mild overflow because generally, the cold coolant level is about two inches below the cap, for expansion. Once this two inch level is obtained, the system generally does not overflow, unless an usually hot ambient temperature and the engine has just been shut off right after a freeway run without a couple minutes of idle cooldown, then maybe a few tablespoons.
A good check of coolant sytem pressure being maintained, with a rag in hand, squeeze the upper rad hose. It should be tight - solid to the squeeze. If not, replace rad cap with a good min 16 lb cap. The higher pressure increases the coolant boiling point, 3°F for every pound of pressure, ie, with 16 lb cap, boiling point goes from 212°F to 260°F.
Of course, an easy fix would be to add an overflow tank and keep tabs of the coolant level in the tank to monitor coolant being used, or not. Then the radiator can be filled to the brim with coolant and go from there as a reference point.