Chapter 33 of the General Laws is hereby amended by inserting after section 59A the following section:-

Section 59B. (a) An employee in the service of the commonwealth or a county, city, town or regional school district that accepts this section pursuant to subsection (b), shall be entitled to a military leave of absence to attend basic training to become a member of the armed forces of the commonwealth, the army national guard, the air national guard or a reserve component of the armed forces of the United States and shall not lose any seniority or any accrued vacation leave, sick leave, personal leave, compensation time or earned overtime. The commonwealth or a county, city, town or regional school district that accepts this section shall pay an employee who is eligible for leave pursuant to this section the employee’s base salary for each pay period during the leave, reduced by any amount received from the United States as pay or allowance for military service performed during the same pay period, excluding overtime pay, shift differential pay, hazardous duty pay or any other additional compensation. Any absences accrued after the completion of basic training but during a pay period for which an employee is paid pursuant to this section shall be considered vacation, sick, personal or unpaid leave.

(b) This section shall take effect in a county, city or town upon its acceptance: in a county, by vote of the county commissioners; in a city or town, as provided in section 4 of chapter 4; and in a regional school district, by vote of the school committee. Nothing in this section shall limit or reduce a person's entitlement to benefits pursuant to section 59  or entitle a person to be released from his work with compensation pursuant to section 59A .

(c) Notwithstanding any general or special law to the contrary, state agencies and municipal governments may expend in the current fiscal year associated costs incurred pursuant to this section in prior fiscal years.