So does that mean if a 19 year old has sex with a 17 year old, that's pedophilia? Because the law says no.
In some states that's a no in others that's a yes.
The problem is a confusion between several legal vs ethical vs psychosexual terms.
A 19 with 17 is not psychosexually pedophilic at all unless the 17 is significantly young looking for their age and underdeveloped (or worse, underdeveloped intellectually and the naivety is what's being preyed on). It also would not entirely be correct to deem it hebophilia since a 19 year old male has only just outgrown being insufficiently finished in puberty themselves (females who are 19 have finished puberty fully already at 16 normally, males tend to kind of 'wane out' their puberty some guys only really finish it at around 22, this includes facial hair development, muscles going from flexible to tough etc).
As for the law, the term is statutory rape and it is very important for you to know that even if your particular state legalises that as long as the 17 year old admits in court they consented, it is a very grey area and flat out illegal in other states. 17 is the bare minimum across US for the more lenient states, usually.