one primary reason the government patents things is to protect themselves from paying licenses/royalties later for things they've already funded. I.e., most contracts stipulate that if the government funded a development that was patented, even by contractor, the government retains royalty free usage of the invention. Similarly, if they patent something they invented, it guarantees no one can 'invent' it later and charge for use (a CYA patent). Of course, the government can collect royalties on patented inventions, and often does so. even give the inventors a decent royalty share, compared to most companies which give you an 'attaboy'.