(dissenting). I respectfully dissent
The parties submitted this dispute to the trial court for resolution on cross-motions for summary disposition on stipulated facts. It appears that the University of Michigan Medical Center (the hospital) provided medical services to a dependent of an employee of plaintiff Oven-Fresh Bakeries, Inc., which dependent was covered under the Oven-Fresh medical insurance plan provided or administered by plaintiff Shield Benefit Administrators, Inc. The hospital billed plaintiffs for these services. In apparent error, Shield Benefit sent payment in excess of that allowed under the terms of the insurance plan. When Shield Benefit sought reimbursement for the overpayment, the hospital declined and this litigation ensued. On the stipulated facts, the circuit court concluded that reimbursement was required in accordance with a line of Michigan cases, including Montgomery Ward & Co v Williams, 330 Mich 275; 47 NW2d 607 (1951).1
If, in our state’s jurisprudence, any legal rule could be said to be “well settled,” the equitable principle referenced in Montgomery Ward is such a rule. It has been a part of our jurisprudence since at least 1886. See Lane v Pere Marquette Boom Co, 62 Mich 63, 67; 28 NW 786 (1886). The rule has been stated as follows:
*474It is well settled law that a payment, although voluntarily made, if made under a mistake of a material fact, may be recovered, even if the mistake be due to a lack of investigation. [Couper v Metropolitan Life Ins Co, 250 Mich 540, 544; 230 NW 929 (1930).]
An exception to this rule has also been recognized: The recipient of the mistaken payment may retain it when the recipient has changed position in detrimental reliance on the payment. Leute v Bird, 277 Mich 27, 31; 268 NW 799 (1936). The stipulated facts submitted in this case indicate that the hospital did not assert or rely upon the detrimental reliance exception.
It is suggested by the hospital that the line of Michigan cases including Montgomery Ward should be supplanted by our adoption of Restatement, Restitution, § 14(1).2 Restatement, Restitution, § 14(1), contrary to the Michigan rule referenced in Montgomery Ward, allows an innocent creditor to retain a mistaken payment made by a third person that discharges the debt of another without the necessity of showing detrimental reliance. I am unconvinced that the Michigan rule is inadequate, as contended, to cover sufficiently and equitably the circumstances of this case. As a rule of equity, it seems reasonable to require the return of a mistaken payment, particularly when the payee can demonstrate no change of position or detrimental reliance as a consequence of receiving the mistaken payment. Such has been Michigan’s rule for more than one hundred years, and it is well understood.
*475Moreover, I have substantial concern about the competence of this Court to make the policy choice it has today adopted. I know that we have very little basis on the record before us to assess the effect of the new rule the majority has embraced. I believe it particularly important when adopting changes in our common law that the Court fully assess the effect of that change.3
I am especially mindful of the fact that neither party addressed the implications of the effect on commerce that the adoption of the Restatement position would occasion. Indeed, when asked at oral argument what these effects might be, counsel for the hospital indicated that she had not considered the issue. The majority, for its part, has not bothered to consider or discuss the potential effect of its decision.
While the Restatement position may be an entirely salutary rule, I cannot help but think that this change in our common law (particularly in the insurer/healthcare provider world that is involved in *476this case)4 will result in a substantially diminished interest on the part of insurers to make any payments before the entirety of an insured’s medical bills have been audited. Otherwise, under the rule adopted today by the majority, a mistaken payment will be retained. Assessing the merits of the tradeoff between the policy choices involved (by way of example only, promoting early, but perhaps some mistaken, payments to providers versus encouraging completely accurate payments to providers) is precisely the kind of task that the Legislature, with input from the public, is most competent to undertake. The reluctance of this Court to modify the common law should be especially strong when a rule of long standing is involved and the consequences of changing that rule are unclear.
Consequently, while I concede that it is within the power of this Court to add to the common law as the majority has done, for prudential reasons I would decline the hospital’s invitation, leave our current common-law remedy in place, and recommend that defendant seek- a legislative change in our laws.
Montgomery Ward, supra, in reliance on earlier Supreme Court precedent, held that a voluntary payment made under a mistake of fact may be recovered, even if the mistake was a product of a failure to investigate. Id. at 284. This rule has apparently never been rejected by the Supreme Court. The equitable foundation for the rule has been varyingly characterized as being derived from a restitution principle as well as serving the avoidance of unjust enrichment. See Hofmann v Auto Club Ins Ass'n, 162 Mich App 424, 429; 413 NW2d 455 (1987).
The text of the Restatement is quoted in the majority opinion, ante at 470.
By way of example, I note the case of Toussaint v Blue Cross & Blue Shield of Michigan, 408 Mich 579; 292 NW2d 880 (1980). Although motivated by honorable intentions, our Supreme Court launched almost two decades of litigation and tremendous tumult in the fabric of Michigan’s contract law when it announced its decision in Toussaint. After more than seventeen years, we are still trying to define the contours of the “Toussaint doctrine.” See, e.g., Lytle v Malady, 456 Mich 1; 566 NW2d 582 (1997). The significant point to be made is that it is hard to identify the legal principle that Toussaint was intended to vindicate that centuries old quasi-contract doctrines (such as detrimental reliance) could not have adequately addressed. Given that our decision making in the common-law area can have profound, expensive, and dislocating effect as the Toussaint example illustrates, I believe that the judiciary is obligated to perform exacting cost-benefit analyses of new common-law rules it adopts to ensure that the new rule truly provides more “cure” than that afforded by the existing rules. I do not believe that the record in this case provides a basis for such an analysis.
The new common-law position the majority adopts today is not limited to the health insurance reimbursement field. Given that little thought has been given to the effect of the majority’s new rule in that field, absolutely no consideration of its effect in other fields has been contemplated.