The Medical School may expand its third-year program next year by accepting more transfer students from Yale and Dartmouth Medical Schools, Henry C. Meadow, assistant dean of the school, said yesterday.

An arrangement whereby students would study for the first two years at another medical school and then transfer to Harvard "is under discussion," Meadow said. No substantial increase, however, in the number of first-year students is planned, he added.

"There is room for growth during the two upperclass years," Meadow explained, "chiefly because there is ample clinical space in the Boston hospitals, where upperclassmen do most of their work." At present the school takes on an additional 15 transfer students for the last two years, Meadow said, but it could take on more.

One possibility, he pointed out, is that Yale, which had limited clinical facilities, might expand its program for the first two years, and send its excess students to Harvard. A similar arrangement might be worked out with Dartmouth, a two-year medical school, which annually sends about half of its graduating class to Harvard.

Expansion in the first two years, however, is limited by the size of the familty and the available building space, Meadow said.