Exhibit (15) August 6, 1996 USG Corporation 125 South Franklin Street Chicago, Illinois 60606 Gentlemen: We are aware that USG Corporation has incorporated by reference into previously filed Registration Statement Numbers 33-40136 and 33-64217 on Form S-3 and 33-22581, as amended, 33-22930, 33-36303, 33-52573, 33-52715, 33-63554 and 33-65383 on Form S-8 its Form 10-Q for the quarter ended June 30, 1996, which includes our report dated July 18, 1996, covering the unaudited condensed financial information contained therein. Pursuant to Regulation C of the Securities Act of 1933, these reports are not considered a part of the registration statement prepared or certified by our firm or reports prepared or certified by our firm within the meaning of Sections 7 and 11 of the Act. Very truly yours, /s/ Arthur Andersen LLP ARTHUR ANDERSEN LLP