The board of trustees of the University of Massachusetts, in conjunction with the University of Massachusetts Medical School, shall develop and implement provisions for payback in learning contracts entered into by students admitted for the academic year commencing in two thousand and fifteen and for every year thereafter, which shall require payback service, so-called, of at least four years within the commonwealth in areas of primary care, public or community service, or underserved areas, as determined by the commissioner of the department of public health and the learning contract committee, in coordination with the area health education center and state and regional health planning agencies. The commonwealth, not the medical school, shall bear the cost of these learning contracts. In the case of any student who has entered into a learning contract and who does not perform payback service, the difference between the tuition actually paid and the amount of the tuition which would have been otherwise charged shall be required to be repaid to the medical school together with eight percent interest per annum and the medical school shall remit the repayment proceeds to the commonwealth; provided, however, that no payback service or tuition loan repayment shall be required prior to the termination of any internship and residency requirements; provided, further, that interest shall begin to accrue upon completion of any internship requirements. The chancellor shall provide, on an annual basis, a report outlining the number of students participating in said learning contracts, the area of medicine within which payback shall be performed, the effects of payback in the underserved areas of the commonwealth, the number of students utilizing the repayment option, and the aggregate tuition which would have been received by the medical school had students not participated in said learning contracts. Said report shall be submitted annually to the house and senate committees on ways and means by September first.