X0306 4 2018-02-24 0 0001163302 UNITED STATES STEEL CORP X 0001626567 Greenstein Sara A. 600 GRANT STREET PITTSBURGH PA 15219 0 1 0 0 Sr. VP - Consumer Solutions Common Stock 2018-02-24 4 F 0 320 44.77 D 45704 D Common Stock 2018-02-24 4 F 0 2957 44.77 D 42747 D Common Stock 2018-02-26 4 M 0 2757 24.78 A 45504 D Common Stock 2018-02-26 4 S 0 2757 45.05 D 42747 D Common Stock 574.167 I By 401(k) plan Common Stock Option 24.78 2018-02-26 4 M 0 2757 0.00 D 2018-02-24 2025-02-24 Common Stock 2757 0 D This line reflects the tax withholding on the vesting of restricted stock units (RSUs) that were granted on February 24, 2015. RSUs vest ratably over a three year period. This line reflects the disposition of shares for tax withholding purposes in connection with the vesting of RSUs that were granted on February 24, 2015 as part of a new hire grant. RSUs cliff-vest on third anniversary of the grant date. RSUs are payable in stock only. This transaction reported on this row was completed pursuant to the terms of a 10b5-1 plan. Option grant vests ratably over three years, one-third on each of the first, second and third grant date anniversaries. /s/ Megan Bombick by power of attorney 2018-02-27