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 New Mexico, 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. The courts in New Mexico will look at the circumstances of each case to determine if an implied or quasi-contractual obligation exists, which would require the party who received the benefit to make restitution. The claim for unjust enrichment does not depend on the presence of wrongful conduct but rather on the notion that it is against equity and good conscience for the enriched party to retain the benefit without compensating the other party. The key consideration is whether, under the law and principles of fairness, the party who paid or conferred the benefit should be compensated because the retention of the benefit by the other party would be unjust.