Exhibit 15

Securities and Exchange Commission

100 F Street, N.E.

Washington, DC 20549

Commissioners:

We are aware that our report dated July 26, 2018 on our review of interim financial information of Raytheon Company, which appears in this Quarterly Report on Form 10-Q, is incorporated by reference in the Registration Statements on Form S-3 (File Nos. 333-211878; 333-71974; 333-58474; 333-82529 and 333-44321) and Form S-8 (File Nos. 333-168415; 333-124690; 333-64168; 333-52536; 333-56117 and 333-45629) of Raytheon Company.

Very truly yours,

/s/ PricewaterhouseCoopers LLP

PricewaterhouseCoopers LLP

Boston, Massachusetts

July 26, 2018