Mich. Const. art. V, § 18

The governor shall submit to the legislature at a time fixed by law, a budget for the ensuing fiscal period setting forth in detail, for all operating funds, the proposed expenditures and estimated revenue of the state. Proposed expenditures from any fund shall not exceed the estimated revenue thereof. On the same date, the governor shall submit to the legislature general appropriation bills to embody the proposed expenditures and any necessary bill or bills to provide new or additional revenues to meet proposed expenditures. The amount of any surplus created or deficit incurred in any fund during the last preceding fiscal period shall be entered as an item in the budget and in one of the appropriation bills. The governor may submit amendments to appropriation bills to be offered in either house during consideration of the bill by that house, and shall submit bills to meet deficiencies in current appropriations.