CFR > Title 20 - Employees' Benefits > CHAPTER II—RAILROAD RETIREMENT BOARD > SUBCHAPTER B—REGULATIONS UNDER THE RAILROAD RETIREMENT ACT (parts 201 to 295) > PART 225—PRIMARY INSURANCE AMOUNT DETERMINATIONS > SUBPART F—Recomputing PIA's (§225.50 to §225.58) > 225.51—PIA's that are subject to recomputation.