I fly CO regularly on tickets booked through COs federal government business ticket engine. I haven't seen Y fares lately (especially on the DCA routes), its been a bunch of H's with the exception of LAX. Mind you this travel is originating from MFE so that could have some affect. I do notice that Y fares pop up for govt. intra-Texas flights but I am rarely on those for official business except occasionally to IAH. Our travel policy, or at least mine, allows for travel on any airline of our choice with the rule that we must book a government fare.