ITC stands for Investment Tax Credit, which is a federal tax credit claimed against the tax liability of residential, commercial, and utility investors in solar energy property. The ITC is a dollar-for-dollar reduction in the income taxes that a person or company would otherwise pay the federal government, based on the amount of investment in solar property. The ITC is one of the most important federal policy mechanisms to support the deployment of solar energy in the United States, and it has helped the U.S. solar industry grow by a factor of more than 200x since it was implemented in 2006, with an average annual growth of 33% over the last decade alone.

It is important to note that ITC can also refer to the International Trade Commission, which is a US government organization that makes rules controlling imports and exports. However, in the context of solar energy, the Investment Tax Credit is the more commonly referred to meaning of ITC.