The One Big Beautiful Bill Act (OBBBA), signed into law on July 4, 2025, set July 4, 2026 as a firm deadline. Sign a commercial solar contract by July 4, 2026 and you're safe harbored for the full §48E credit (conditions apply) — with until December 31, 2030 to place the system in service.
Any contract signed after July 4, 2026 must be placed in service by December 31, 2027 to qualify for the tax credit. That’s just 18 months, or less.