Mummert answered two questions wrong in the verbal section of the test, but test-takers can miss four in the verbal section and one in math and still receive a perfect score.
The test is used by most colleges to evaluate applicants.
After taking the test, Mummert said he knew he got at least one answer wrong in the verbal section and confirmed it when he got home and looked up a word in the dictionary. But overall, he said he was confident about his test results.
"When I took the test I knew I did well on it," he said.
Mummert took the PSATs in the fall of 1996 and scored 1,450. He followed up with the SAT last spring, ending up with a score of 1,430.
"I didn't think that was my best effort," he said, so he took the test again last fall.
Chambersburg school officials believe Mummert is the first student in the district in the past 20 years to get a perfect score on the SAT.
"I'm obviously very proud and, from an educator's standpoint, very excited for Phil ... I'm very impressed with how well he did," said Dennis Hillwig, high school principal.
Hillwig described Mummert as a "very good and very serious" student.
A straight-A student from kindergarten, Mummert said his knowledge comes naturally and he rarely studies.
"His brothers and sisters taught him a lot, but of course he picked it up easy ... He could read before he went to school," said his mother, Claire.
Mummert is the youngest of five children of Gerald and Claire Mummert.
The normally quiet and shy teenager has received a lot of attention since the announcement of his perfect score. He's become the constant source of jokes by his friends and the recipient of a bunch of congratulatory mail "from people I don't know," but it hasn't gone to his head.
"I don't think it's changed me," Mummert said.
He takes advanced classes in school, ranking math and this year's advanced chemistry class as his favorite subjects.
At school, Mummert plays trumpet in the jazz, marching and concert bands, in which he also is section leader. He also sings in the glee club and accompanies on the piano.
At Chambersburg Bible Church, Mummert participates in the basketball and softball leagues as well as in the music programs there.
In between school and his activities, he works on the family dairy farm, usually milking the 85 cows and doing other general chores.
It's the independence he's learned from growing up on a farm that has Mummert thinking he'd like to be his own boss, possibly owning his own business, maybe in the computer science industry. But he hasn't ruled out working on the farm for a living.
"I don't know what to do yet," he said.
At this point, Mummert isn't even sure he wants to go to college. But he has applied to Rose-Hulman Institute of Technology in Terre Haute, Ind., and is thinking about looking at some Bible colleges.