Relative to creating a MassHealth buy in program. Notwithstanding any general or special law to the contrary, the office of Medicaid shall establish and offer an optional expanded Medicaid plan for purchase by an individual or by an employer as an employer-sponsored insurance plan. The optional expanded plan may set alternate eligibility and cost-sharing standards beyond those established by section 9A of chapter 118E of the General Laws and may condition participation in the program; provided, however, that any optional expanded plan offered to an employer shall require the employer to pay not less than 50 per cent of the projected cost of coverage for participating employees. The office may adjust benefits offered through an optional plan under this section; provided, however, that the office shall maintain the benefit and cost-sharing standards for those individuals and employees that meet the eligibility standards established by said section 9A of said chapter 118E.