The commissioner of management and budget may develop and implement a program that creates an incentive for efficient use by state employees of State Employee Group Insurance Program (SEGIP). The program may reward employees covered by SEGIP as a group if per capita employee health care costs paid by SEGIP for a calendar year prove to be less than estimated by the commissioner prior to the beginning of the calendar year. The reward may consist of payments of one-half of the cost-savings into the employees’ health reimbursement accounts, to be made no later than June 30 of the following calendar year.