The following is the Oct. 22, 2018 Congressional Research Service report, Navy Virginia (SSN-774) Class Attack Submarine Procurement: Background and Issues for Congress.
From the report
The Navy has been procuring Virginia (SSN-774) class nuclear-powered attack submarines (SSNs) since FY1998. The two Virginia-class boats that the Navy has requested for procurement in FY2019 would be the 29th and 30th boats in the class, and the first two to be covered under a multiyear procurement (MYP) contract...
https://news.usni.org/2018/10/23/report-congress-virginia-class-attack-submarine-program-6