Soon after his arrival in the United States from Oslo, radical psychoanalyst Wilhelm Reich became the subject of intensive inquiry by the Federal Bureau of Investigation. Part of what motivated the FBI's case against Reich was an anonymous claim that he had been a member of the Norwegian Communist Party. The initial investigation led to Reich's arrest and detention for nearly a month after the United States declared war on Germany in December, 1941. Some years later, after Reich became a naturalized citizen of the United States, a more extensive investigation occurred, this time by the Immigration and Naturalization Service. The INS looked to strip Reich of his citizenship, and central to their efforts was the very same anonymous claim about his membership in the Norwegian Communist Party. In this essay, relying upon US government documents, Reich's reported membership is examined and its veracity assessed.