When are patent applications published?

Patent applications are generally published 18 months after the earliest filing date, with some exceptions. According to 35 U.S.C. 122(b)(1)(A):

“Subject to paragraph (2), each application for a patent shall be published, in accordance with procedures determined by the Director, promptly after the expiration of a period of 18 months from the earliest filing date for which a benefit is sought under this title. At the request of the applicant, an application may be published earlier than the end of such 18-month period.”

Exceptions to publication include applications that are no longer pending, subject to a secrecy order, provisional applications, or design patent applications.