Private insurers have good reason, both in their private interest and in the public interest, for pursuing and rooting out fraud in the healthcare system; moreover, they often have sophisticated data systems, substantial investigative information, and management expertise that can be useful to prosecutors. It makes sense, as a public policy matter, to undertake steps to encourage insurers to be aggressive in pursuing legitimate fraud cases, and to provide a framework for effective cooperation and information sharing with law enforcement. At the same time, prosecutors are responsible for enforcing equal justice under the law; thus, any such relationship must be handled in an appropriate manner, with safeguards to protect privacy and the reputation of investigative subjects. While the courts have not yet explored many of the relevant legal and factual issues in this area, the author surveys existing guidance under governing laws and policies applicable to state and federal prosecutors, and suggests techniques to prevent inappropriate communication or use of such information.