Section 5 of chapter 59 of the General Laws as appearing in the 2012 Official Edition is hereby amended by striking out clause twenty-second D and inserting in place thereof the following clause:

Twenty-second D, Real estate to the full amount of the taxable valuation of real property of the surviving spouses of soldiers and sailors, members of the National Guard and veterans whose death occurred as a  result of an injury or disease documented by the department of defense or the department of veterans affairs to have been sustained or contracted in a combat zone or while serving on active duty, or who are missing in action with a presumptive finding of death, as a result of combat as members of the armed forces of the United States, if the real estate is occupied by the surviving spouse as a domicile, and if the surviving spouse has been domiciled in the commonwealth for 5 consecutive years next before the date for filing for exemption under this clause or the soldier or sailor or member of the National Guard was domiciled in Massachusetts for at least 6 months before entering service.

Such exemption shall be available to said spouses of soldiers and sailors, members of the National Guard and veterans who died before or after the effective date of this legislation but shall apply only to taxes being assessed on or after July 1, 2015 or until such time that the surviving spouse dies or remarries.

No real estate shall be so exempt which has been conveyed to the surviving spouse to evade taxation. The amount of the exemption shall be borne by the commonwealth, and the state treasurer shall annually reimburse the city or town for the amount of the tax which otherwise would have been collected for this exemption.