Thayer and Another v. Life Association of America and Others was a United States Supreme Court case that dealt with the issue of whether a life insurance policy could be voided due to a misrepresentation of age. The plaintiffs, Thayer and another, had purchased a life insurance policy from the defendants, Life Association of America and others. The policy was voided by the defendants after it was discovered that the plaintiffs had misrepresented their age on the application. The plaintiffs argued that the misrepresentation was not material and that the policy should not be voided. The Supreme Court held that the misrepresentation of age was material and that the policy could be voided. The Court reasoned that the misrepresentation of age was material because it affected the risk assumed by the insurer. The Court also noted that the misrepresentation of age was a material fact that was necessary for the insurer to determine the premium rate. The Court concluded that the misrepresentation of age was material and that the policy could be voided.

In Thayer & Another v. Life Association of America & Others, the Supreme Court was tasked with determining whether a life insurance policy could be voided due to misrepresentation by the insured. The majority opinion held that such policies were voidable if there had been any material misstatement or concealment made in order to obtain coverage. However, Justice Field dissented from this decision and argued that while it is true that an insurer has the right to rescind a contract based on fraudulent statements, they should not have such broad authority when it comes to innocent mistakes or omissions made during application for coverage. He further argued that allowing insurers too much power would lead them down a slippery slope where they may take advantage of their customers who are unaware of all relevant facts related to their policy and thus unable to make informed decisions about what type of coverage best suits them.