From Military.com:

Boeing plans to start building components for the first Air Force KC-46A tanker this fall and is looking to begin assembling the first aircraft one year from now.

The Pentagon’s KC-46A selected acquisition report, a document that provides extensive details of the program’s cost and performance, said the company projects the tanker development phase to cost $5.1 billion, which is $300 million above the Defense Department’s $4.8 billion contract ceiling price.