The PTC can be claimed for the year in which construction began (called “safe harbor”) if continuous progress is made towards completion for and operation begins within up to 4 years (called “continuity safe harbor”). For example, if a project commenced construction in 2019, the developer could claim the 2019 PTC if the facility is operational before the end of 2023 and then take advantage of the tax credit until 2033. In late May 2020, in response to the SARS-coronavirus-2 shutdowns, the Internal Revenue Service extended the continuity safe harbor to 5 years for projects started in 2016 or 2017 (i.e., they have until the end of 2021 or 2022 to complete construction and become operational to claim the 2016 or 2017 PTC) and extended the safe harbor by 3.5 months for projects that would have begun construction (i.e., services or property paid for) from September 16, 2019, to October 15, 2020.<ref>https://www.irs.gov/pub/irs-drop/n-20-41.pdf</ref>
In December 2020, Congress extended the PTC and ITC – at the 2018 rate –
to projects starting construction in 2021.
==Investment tax credit==