In Announcement 2021-10 the IRS provided that qualified opportunity zone (QOZ) boundaries will not be changed due to the recently completed census.[1] 

Since QOZs are based on census tracts, there were some concerns expressed about how the new census would impact QOZs.  The IRS has now stated there will be no changes to QOZ boundaries due to the results of the 2020 Census.

The Announcement first describes the process by which the original QOZ designations were made, based on census tracts from the 2010 Census:

Section 13823 of Public Law 115-97 (December 22, 2017), commonly referred to as the Tax Cuts and Jobs Act, amended the Internal Revenue Code (Code) by adding sections 1400Z-1 and 1400Z-2 to the Code. Section 1400Z-1 provides the rules under which population census tracts located in one of the 50 States, the District of Columbia, or the U.S. territories were required to be nominated by the chief executive officer (CEO) of a State, the District of Columbia, or a U.S. territory and designated as QOZs by the Secretary of the Treasury or his delegate (Secretary). Section 1400Z-1 contains limited timeframes that ended in 2018 by which all nominations by CEOs and designations by the Secretary of QOZs were required to be made. That section also provides special rules for population census tracts located in Puerto Rico.

Notice 2018-48 and Notice 2019-42 set forth lists of the Designated QOZs based on census tract numbers and census tract boundaries that existed as of the respective 2018 and 2019 publication dates of those notices. These census tract numbers and boundaries, as incorporated by reference into Notice 2018-48 and Notice 2019-42, are based on the 2010 decennial census and those boundaries define the boundaries of the Designated QOZs.[2]

The Announcement points out that the law required these QOZs to be designated by a deadline in 2018 and continues:

Section 1400Z-1 does not permit QOZs to be nominated or designated after the statutory deadlines; nor does it permit any post-designation changes to the boundaries of the Designated QOZs. The boundaries of the Designated QOZs were established at the time they were designated and are not subject to change. Accordingly, boundaries of a Designated QOZ do not shrink or expand if the 2020 decennial census results in a change to the boundaries of a census tract. Similarly, if the 2020 decennial census results in a change to a 2010 census tract number listed in Notice 2018-48 and Notice 2019-42 and associated with a Designated QOZ, the 2010 census tract number continues to apply for purposes of identifying the Designated QOZ.[3]

[1] Announcement 2021-10, May 14, 2021, https://www.taxnotes.com/research/federal/irs-guidance/announcements/census-will-not-affect-qualified-opportunity-zone-boundaries/5s7tp (retrieved May 16, 2021)

[2] Announcement 2021-10, May 14, 2021

[3] Announcement 2021-10, May 14, 2021