NY 30A begins at an intersection with NY 30 in northern reaches of the village of Schoharie. Continuing northwest along the former right-of-way of NY 30, NY 30A crosses along Schoharie Creek into exit 23 of I-88, a diamond interchange. Just north of the interchange, the route reaches a junction with NY 7. At this junction, NY 30A turns west onto NY 7 and form a concurrency into the hamlet of Old Central Bridge after crossing Schoharie Creek. Several blocks west of the Schoharie, NY 30A turns north and away from NY 7, crossing north into Central Bridge. After crossing Cobleskill Creek, the route passes east of Central Bridge Community Park and a junction with County Route 51 (CR 51 or South Main Street).