The doctrine of unjust enrichment applies the principles of restitution to disputes that are not governed by a contract between the parties. It characterizes the result of a failure to make restitution under circumstances that give rise to an implied or quasi-contractual obligation to return those benefits.

The courts describe this claim in general principles. For example, courts have stated that a claim for unjust enrichment seeks to restore money where equity and good conscience require restitution; it is not premised on wrongdoing, but seeks to determine to which party, in equity, justice, and law, the money belongs; and it seeks to prevent unconscionable loss to the payor and unjust enrichment to the payee.

Because recovery based on unjust enrichment of another party relies on the court's sense of fairness or equity rather than the law, it is often referred to as the equitable doctrine of unjust enrichment.

In Iowa, the doctrine of unjust enrichment is recognized and applied by courts when one party has received a benefit unjustly at the expense of another, and there is no valid contract governing the transaction between the parties. This doctrine is rooted in principles of equity, aiming to prevent one party from being unjustly enriched at the expense of another. Iowa courts will consider claims for unjust enrichment to determine whether, under the circumstances, it is equitable and just for the recipient of the benefit to retain it or whether they should make restitution to the other party. The claim is not based on the presence of wrongful conduct but rather on the notion that it would be unconscionable for the recipient to keep the benefit without compensating the party who has suffered a loss. The courts will look at the specifics of each case to decide if an implied or quasi-contractual obligation exists, which would require the enriched party to make restitution to the aggrieved party.