Keith Carpenter, 16-year-old St. John's High student who plays out of Congressional, won the medal in the Insurance Youth Classic qualifying tournament for Montgomery and Prince George's counties at Tantallon yesterday. He shot a two-under-par 70.

The other players who qualified for the state final slated for Tantallon July 21, are Bob Biedenkapp, 15, of Andrews Air Force Base, who had a 72; Rhett Butler, 17, Georgetown Prep, who had a 74; and Gregg McGuilouch, 16, Bowie, and Dan McAndrews, 17, Columbia Country Club, each with 75. The top four finishers in the state tournament will qualify for the national final which will be held at Napa, Calif., Aug. 12-15.

A field of 44 golfers teed off in the plus-90 degree heat and the tight Tantallon course gave most of them problems. Only nine broke 80.

Carpenter was out in 34 and home in 36 with four birdies and two bogies. He birdied the first hole, a par five, where he was on the green in two and two-putted. He birdied the second from five feet and the fifth hole from two feet. He bogied the eighth when his nine-iron shot went over the green and the 11th when he hit a poor chip shot. His final birdie came on the 16th when he chipped a foot from the hole.