The federal Investment Tax Credit for commercial solar ends on December 31, 2027. Not reduced — ended. And the date it must be met by is not the date you sign.
The Requirement
Projects that did not begin construction by July 4, 2026 must be placed in service by December 31, 2027.
Placed in service means the system is complete and capable of producing power: installed, inspected, interconnected, and granted Permission to Operate by the utility.
A signed contract does not meet it. A finished installation does not meet it. The utility has to have granted PTO.
Counting Backward
Here is what has to happen before that, using the timelines from our own FAQ:
- Permission to Operate — often about a month, though utility processing varies and cannot be guaranteed
- Inspection by the Authority Having Jurisdiction
- Installation — several days to several weeks depending on size and complexity
- Permit review — days in some jurisdictions, a month or more in others
- Engineering and permit package — about one month
- Initial evaluation of bills, interval data and site — about one week
Run cleanly end to end, that chain wants to start around July 2027. And that version assumes nothing goes wrong.
Where It Actually Slips
Service upgrades. If your electrical service cannot accommodate the new generation, the upgrade brings its own engineering and its own utility queue. It is frequently the longest item in a project, which is why we identify it during evaluation rather than after.
Permit backlogs. Review times vary considerably by jurisdiction under normal conditions. Late 2027 will not be normal conditions — a great many projects will be converging on the same deadline.
The installation calendar. Our own team does the work and we honor commitments to existing customers in the order they were made. As the deadline nears, the schedule fills.
The Practical Date
Add realistic margin and the decision point lands in spring 2027 for a straightforward project — earlier if utility-side work may be involved.
If the credit is part of why the numbers work for you, that is the date worth marking.
One Thing Worth Checking First
If you paid anything toward a solar project before July 4, 2026 — a deposit, an equipment order, a signed commitment — you may be in the other bucket entirely, with until December 31, 2030 to complete.
For systems at or below 1.5 MW, which covers all our commercial work, beginning of construction could be established by incurring a portion of total project cost rather than by physical work on site. Bring the documentation to your tax professional before assuming you missed it.
This is general guidance, not tax advice. Consult your tax professional regarding your eligibility.
Request a free consultation and we will tell you candidly whether your project still fits the window.