Executive summaryIn a private letter ruling (PLR 202135006, released 3 September 2021), the United States (US) Internal Revenue Service (IRS) permitted a taxpayer effectively to undo planning undertaken during a so-called gap period (described later).After many taxpayers implemented gap period strategies in 2018, the US Department of the Treasury (Treasury) and the IRS in 2019 issued regulations (the extraordinary disposition regulations) under Internal Revenue Code[i] Sections 245A and 954(c)(6) that retroactively neutralized, and in some cases penalized, gap period strategies. In the newly released PLR, the IRS granted the taxpayer's request to make a late entity-classification election (familiarly, a check-the-box...