(a) There is hereby levied and imposed an excise tax on the gross receipts or gross proceeds derived by health care providers enrolled in this state's medical assistance program. The amount of the tax shall be equal to one hundred percent of that portion of gross receipts paid to the health care provider by the single state agency from state revenues for all services delivered pursuant to Title XIX of the United States Social Security Act, to individuals who, at the time such services were delivered, were enrolled with the single state agency and eligible to receive Medicaid services, whether such health care provider is located within or without this state or such service is delivered within or without this state: Provided, That the following are not subject to the tax imposed in this article:
(1) Gross receipts or gross proceeds derived by a health care provider from delivering cost-based services;
(2) That portion of a health care provider's reimbursement when the secretary certifies the state share so that the Medicaid reimbursement consists solely of federal financial participation, except that any gross receipts or gross proceeds derived by a health care provider from delivering Medicaid services that are not reimbursed on a certified match basis are taxable under this article: Provided, That nothing in this section prohibits the department from removing a service, or provider group, from the certified match program and placing that service, or provider group, under full Medicaid payments subject to the tax imposed by this article; and
(3) Employees or agents of a health care provider when that employee or agent does not directly receive the Medicaid reimbursement payment.
(b) The tax imposed by this section applies solely and exclusively to that portion of the Medicaid reimbursement payment made from state revenue for services delivered by the health care provider pursuant to Title XIX of the United States Social Security Act, as amended, which amount shall be determined as provided in subsection (c) of this section.
(c) From time to time, as is necessary, the secretary shall notify the Tax Commissioner in writing of the portion, stated as a uniform percentage, of each Medicaid reimbursement payment taxable under this article that constitutes the state's share of Medicaid program financial obligations in order to determine and tax only the state revenue share of that Medicaid reimbursement payment. After receipt of such notice, the Tax Commissioner shall immediately cause to be published in the state register notice of that percentage and its effective date for purposes of calculating the tax imposed by this article. Beginning January 1, 1992, and continuing until a notice of change in this percentage takes effect, the state revenue share of a Medicaid reimbursement is twenty-two and thirty-two hundredths percent, except as otherwise provided in this article.