Periodic adjustments
(6) Periodic adjustments(i) In general. Subject to the exceptions in paragraph (i)(6)(vi) of this section, the Commissioner may make periodic adjustments for an open taxable year (the Adjustment Year) and for all subsequent taxable years for the duration of the CSA Activity with respect to all PCT Payments, if the Commissioner determines that, for a particular PCT (the Trigger PCT), a particular controlled participant that owes or owed a PCT Payment relating to that PCT (such controlled participant being referred to as the PCT Payor for purposes of this paragraph (i)(6)) has realized an Actually Experienced Return Ratio (AERR) that is outside the Periodic Return Ratio Range (PRRR). The satisfaction of the condition stated in the preceding sentence is referred to as a Periodic Trigger. See paragraphs (i)(6)(ii) through (vi) of this section regarding the PRRR, the AERR, and periodic adjustments. In determining whether to make such adjustments, the Commissioner may consider whether the outcome as adjusted more reliably reflects an arm's length result under all the relevant facts and circumstances, including any information known as of the Determination Date. The Determination Date is the date of the relevant determination by the Commissioner. The failure of the Commissioner to determine for an earlier taxable year that a PCT Payment was not arm's length will not preclude the Commissioner from making a periodic adjustment for a subsequent year. A periodic adjustment under this paragraph (i)(6) may be made without regard to whether the taxable year of the Trigger PCT or any other PCT remains open for statute of limitations purposes or whether a periodic adjustment has previously been made with respect to any PCT Payment.