A signed proposal does not necessarily preserve a rebate. Programs can use a preapproval date, installation date, invoice date, placed-in-service date, or application-submission date.
Before work begins
Power Ahead Colorado requires an approved contractor to submit the project for preapproval before work begins. Its official process says the program verifies the project and rebate amount, then the contractor completes the work and submits final documentation. The customer later confirms whether payment goes to the customer or contractor.
Denver's published residential program also describes contractor preapproval, but the current page still reports its 2025 allocation as fully subscribed. Do not treat that old cycle as a current Denver offer.
At installation and invoice
Save the final paid invoice, not only the proposal. It should identify the installation address, dates, exact model numbers, cost, and each discount. Save the AHRI certificate and manufacturer specification sheets used to establish eligibility.
Xcel's digital application says invoices and equipment specification documents must be attached. The application page is an entry point; it does not independently prove that a model qualifies.
The September 30 transition
The temporary 2026 Xcel cold-climate amount is reported at $2,250 per heating ton at 5°F through September 30, then $1,500 per heating ton beginning October 1. Before relying on the higher amount, obtain Xcel's current written rule for:
- the last eligible installation and invoice date;
- the application-submission cutoff;
- treatment of ducted, partially ducted, whole-home ductless and supplemental systems; and
- the capacity and equipment documentation required.
Federal dates changed
The IRS says Section 25C is not allowed for property placed in service after December 31, 2025. A heat pump, furnace, central air conditioner or enabling electrical project installed in 2026 does not receive the former residential improvement credit.