  Active discussion on the high energy physics priorities in the US carried out
since summer of 2013 resulted in changes in Fermilab plans for future
development of the existing accelerator complex. In particular, the scope of
Project X was reduced to the support of the Long Base Neutrino Facility (LBNF)
at the project first stage. The name of the facility was changed to the PIP-II
(Proton Improvement Plan). This new facility is a logical extension of the
existing Proton Improvement Plan aimed at doubling average power of the
Fermilab's Booster and Main Injector (MI). Its design and required R&D are
closely related to the Project X. The paper discusses the goals of this new
facility and changes to the Project X linac introduced to support the goals.
