Beltway bandit

noun3

1. •
   (informal) A consulting or research company that mostly carries out work for US government departments or agencies.

   • He worked for a beltway bandit firm, doing engineering work. He computed trajectories on missiles... that kind of thing. — 2001
2. •
   (informal) An employee of such a firm, especially a former employee of the firm's clients.
3. •
   (informal) A short-term money lender to contractors working for the US government but waiting for US congressional appropriations.

   • [He] turned out to be what is called a "Beltway bandit," lending money at short-term high (but legal) rates to government contractors low on cash who are awaiting congressional appropriation funding. — 1999