New York Life Insurance Company v. Fletcher was a United States Supreme Court case that addressed the issue of whether a life insurance policy could be assigned to a third party. The case involved a policy issued by the New York Life Insurance Company to a man named Fletcher. After Fletcher's death, his widow attempted to assign the policy to a third party, but the insurance company refused to recognize the assignment. The Supreme Court ultimately held that the policy could not be assigned to a third party, as the policy was a personal contract between the insurance company and Fletcher. The Court reasoned that the policy was not transferable, and that the widow had no right to assign it to a third party. The Court also noted that the policy was not a negotiable instrument, and that the widow had no right to assign it to a third party without the consent of the insurance company. The Court's decision established that life insurance policies are not transferable, and that the policyholder's rights are personal and cannot be assigned to a third party.

In New York Life Insurance Company v. Fletcher, the Supreme Court was asked to decide whether a life insurance policy issued by an out-of-state company could be enforced in another state. The majority of the court held that it could not, as such policies were prohibited under a Tennessee statute which required all life insurance companies doing business in the state to have their principal office there. In his dissenting opinion, Justice Field argued that this decision violated both due process and contract clauses of the Fourteenth Amendment since it deprived individuals from other states who had entered into valid contracts with out-of-state insurers of their property without due process or just compensation. He further argued that if one state can pass laws prohibiting citizens from other states from entering into valid contracts with companies located outside its borders then no citizen would be safe when traveling or conducting business across different jurisdictions.