Yes, there is a parking lot right across the street from the Inn at the Long Trail (where Sherburne Pass Trail, the blue-blazed trail over Pico comes out -- also known as the "old LT.") There is also another parking lot about a mile up the road where the current route of the AT/LT crosses Route 4.
Not only is there parking, but also the best pint of Guinness on the AT. If you do not stop into the Pub at the Inn at Long Trail you will be very sad.