Section 1.431(c)(6)-1 - Mortality tables used to determine current liability(a)Mortality tables used to determine current liability. In accordance with section 431(c)(6)(D), the mortality assumptions that apply to a single-employer defined benefit plan for the plan year pursuant to section 430(h)(3)(A) and (D) and §§ 1.430(h)(3) -1(a)(1) and (a)(2)(ii) are used to determine a multiemployer plan's current liability for purposes of applying the rules of section 431(c)(6). For purposes of this paragraph (a), either the generational mortality tables used pursuant to § 1.430(h)(3) -1(b) or the static mortality tables used pursuant to § 1.430(h)(3) -1(c) are permitted to be used without regard to whether the plan is a small plan. However, substitute mortality tables under §§ 1.430(h)(3) -1(a)(2)(i) and 1.430(h)(3)-2 are not permitted to be used for purposes of this paragraph (a).(b)Applicability date. This section applies for valuation dates occurring on or after January 1, 2024.T.D. 9983, 88 FR 72366, Oct. 20, 2023 T.D. 9826, 82 FR 46410, 10/5/2017; T.D. 9983, 88 FR 72366, 10/20/2023