Text of IRS Notice 2017-60: Updated Static Mortality Tables for Defined Benefit Pension Plans for 2018 (PDF)
"This notice sets forth the mortality table that is used for purposes of determining minimum present value under Section 417(e)(3) of the Internal Revenue Code and section 205(g)(3) of [ERISA] ... for distributions with annuity starting dates that occur during stability periods beginning in the 2018 calendar year. This mortality table is a modified unisex version of the mortality tables specified under Section 430(h)(3)(A) of the Code, which have been revised pursuant to Section 430(h)(3)(B) by T.D. 9826, for plan years beginning in 2018. This notice also provides updated static mortality tables determined using the methodology in Section 1.430(h)(3)-1 prior to its amendment by T.D. 9826. These updated static mortality tables apply for plan years beginning during 2017 with respect to valuation dates occurring during 2018."
Internal Revenue Service [IRS]

Text of IRS Final Regs: Mortality Tables for Determining Present Value Under Defined Benefit Pension Plans
83 pages. "This document contains final regulations prescribing mortality tables to be used by most defined benefit pension plans.... This information is used ... for purposes of determining the minimum funding requirements for a defined benefit plan. These mortality tables are also relevant in determining the minimum required amount of a lump-sum distribution from such a plan. In addition, this document contains final regulations updating the requirements that a plan sponsor must meet to obtain IRS approval to use mortality tables specific to the plan for minimum funding purposes (instead of using the generally applicable mortality tables)."
Internal Revenue Service [IRS]

Text of IRS Rev. Proc. 2017-55: Procedures for Plan Sponsor to Request Approval for Use of Plan-Specific Substitute Mortality Tables (PDF)
24 pages. "This revenue procedure sets forth the procedure by which the sponsor of a defined benefit plan that is subject to the funding requirements of Section 430 of the Internal Revenue Code may request approval from the [IRS] for the use of plan-specific substitute mortality tables in accordance with Section 430(h)(3)(C) and Section 1.430(h)(3)-2 of the Treasury Regulations.... A request for approval to use substitute mortality tables for a plan that would first apply for a plan year beginning on or after January 1, 2018, must satisfy the requirements of the 2017 regulations and this revenue procedure."
Internal Revenue Service [IRS]