Corporate income tax: credits; research and development credit for certain businesses located in an aerospace defense zone; provide for. Amends 1967 PA 281 (MCL 206.1 - 206.847) by adding secs. 279 & 679.

SB 557 creates tax credits for businesses in Michigan's designated aerospace defense zones. It offers a 30% credit on qualifying research and development expenses (capped at $10 million per business annually) and a 20% credit on storage/maintenance costs for finished goods inventory (capped at $1 million per business annually). To qualify, businesses must be designated by the Michigan Strategic Fund as defense contractors, aerospace manufacturers, or tiered suppliers with under $5 million in annual revenue. The credits require certification from the Strategic Fund, have annual spending limits ($100 million for R&D credits, $25 million for inventory credits), and cannot be claimed on the same expenses as other credits. This bill directly affects small-to-midsize aerospace and defense businesses operating within designated zones in Michigan.