SECTION 1. Section 6 of Chapter 62 of the General Laws, as appearing in the 2004 Official Edition, is hereby amended by adding the following subsection: - (l) A credit shall be allowed against the tax liability imposed by this chapter to a taxpayer who has reached the age of sixty-five or more for the cost incurred by the taxpayer during the tax year for the purchase of prescription drugs.  The credit shall not exceed two thousand dollars per tax year.  Said taxpayer whose prescription drug costs are fully covered by an insurance plan, or the prescription drug insurance plan administered by the Executive Office of Elder Affairs, shall receive the tax credit for their premium or deductible costs.  If the credit provided in this section reduces the tax to zero, the taxpayer shall be entitled to a refund equal to the amount of the credit exceeded the amount of tax due.