When a kid turns 18 is the father still responsible for child support?
Child support usually lasts until age 18 or graduation from High School, whichever occurs later. Some states say that it must end at age 19, even if the child has not graduated. Also, some states allow for extensions (at the judges discretion) when a child is disabled. resulting in a longer general education. There have been proposals in some states to extend support until a child graduates college, but so far these have not been enacted, and are probably unconstitutional if they are ever inacted.
Generally speaking, no, but if there is child support that accumulated prior to a child turning 18, that can still be owing, at least for awhile. A parent can also be ordered to pay for college support in at least some states, and finally,some states impose child support obligations on parents for disabled children.