Forgery, deceive or injure another, he falsely makes, completes or alters a written instrument which is or purports to be. What Is the Punishment for Forging a Signature on a Check?What Is the Difference Between Forgery and Counterfeit? Forgery and fraud cases often involve complex terms with very specific meanings. For example, an instrument can be complete or incomplete. Forgery in the Third Degree, New York Penal Law 170.05, is a misdemeanor crime that carries a sentence of up to one year in jail. Criminal possession of a forged instrument in the third degree is a class A misdemeanor forgery crime and can result in up to one year in jail. Under our law, a person is guilty of Forgery in the Second.