X0306 4 2015-05-29 0 0001163302 UNITED STATES STEEL CORP X 0001553880 Matthews Douglas R 600 GRANT STREET, 61ST FLOOR PITTSBURGH PA 15219 0 1 0 0 Sr VP - N American Flat-Rolled Common Stock 2015-05-29 4 F 0 1643 24.63 D 45085 D Common Stock 5459.398 I By 401(k) plan This line reflects the disposition of shares for tax withholding purposes in connection with the vesting of restricted stock units (RSUs) that were granted on May 29, 2012. RSUs vest ratably over a three year period. /s/ Arden T. Phillips by Power of Attorney 2015-06-02