A person commits forgery if, with intent to defraud, the person: 1. Falsely makes, completes or alters a written instrument; or 2.Most types of forgery are categorized as class 4 felonies. A conviction could mean up to 15 years in prison plus 3 more years of probation. Any document that has been falsified or altered for the purpose of deceiving others is considered a forgery in Arizona. Forgery in Arizona is classified as a class four felony with harsh penalties as outlined below: First-offense-probation with up to one year in jail; or,. Forgery is a Class 4 felony in Arizona, which means a conviction can carry significant penalties, including imprisonment and fines.