45 C.F.R. § 1174.6

The authority may issue a complaint only if:

(a) The Attorney General (or designee) approves the reviewing official's referral of the allegations for adjudication; and

(b) In a case of submission of false claims, if the amount of money or the value of property or services that a false claim (or a group of related claims submitted at the same time) demanded or requested does not exceed $150,000.