According to Bloomberg, in a sign that Mueller is preparing to hand off more of his investigation to other federal prosecutors - like he did with the investigation into Michael Cohen (which he "delegated" to the southern district of New York) - the DOJ is now spending more on supplemental work for Mueller than it is spending on the special counsel's own staff.
According to his most recent statement of expenditures, more money is being spent on work done by permanent Department of Justice units than on Mueller's own dedicated operation. The DOJ units spent $9 million from the investigation's start in May 2017 through March of this year, compared with $7.7 million spent by Mueller's team.
Mueller is also increasingly depending on investigators in different areas, including New York, Alexandria, Va. and Pittsburg, Penn. in yet another sign that another handoff could be imminent.
Investigators in New York; Alexandria, Virginia; Pittsburgh and elsewhere have been tapped to supplement the work of Mueller's team, the officials said. Mueller has already handed off one major investigation - into Trump's personal lawyer, Michael Cohen - to the Southern District of New York.