; (2) by striking , would be denied or reduced as a result of a bankruptcy proceeding commenced in 2012 or 2015 in clause (ii)(II) and inserting or a related coal wage agreement, would be denied or reduced as a result of a bankruptcy proceeding commenced in 2012, 2015, or 2018 ; (3) by striking January 1, 2017 in clause (ii) and inserting January 1, 2018 ; and (4) by adding at the end the following new clause: (vi) Related coal wage agreement For purposes of clause (ii), the term related coal wage agreement means an agreement between the United Mine Workers of America and an employer in the bituminous coal industry that— (I) is a signatory operator; or (II) is or was a debtor in a bankruptcy proceeding that was consolidated, administratively or otherwise, with the bankruptcy proceeding of a signatory operator or a related person to a signatory operator (as those terms are defined in section 9701(c) of the Internal Revenue Code of 1986). . 4. Reduction in minimum age for allowable in-service distributions (a) In general Section 401(a)(36) of the Internal Revenue Code of 1986 is amended by striking age 62 and inserting age 59 ½ . (b) Application to governmental section 457 (b) plans Clause (i) of section 457(d)(1)(A) of the Internal Revenue Code of 1986 is amended by inserting (in the case of a plan maintained by an employer described in subsection (e)(1)(A), age 59 ½ ) before the comma at the end. (c) Effective date The amendments made by this section shall apply to plan years beginning after December 31, 2017. 5. Black Lung Liability Trust Fund excise tax (a) In general Section 4121(e)(2)(A) of the Internal Revenue Code of 1986 is amended by striking December 31, 2018 and inserting December 31, 2028 . (b) Effective date The amendment made by this section shall apply to sales after December 31, 2018.