How many years of cohabitation are required for a couple to establish a common law marriage?

The number of years of cohabitation required for a couple to establish a common law marriage varies by state, with some states not recognizing common law marriage at all. In states that do recognize common law marriage, typically 7 to 10 years of cohabitation is considered sufficient to establish a common law marriage. It is important to note that the specific requirements can vary, so it is advisable to consult the laws of the state in question for accurate information.