Identify where the inmate is incarcerated. If you do not know, call the correctional agency that you think is most likely to be responsible for the inmate. For instance, an inmate convicted of a state crime in Florida would most likely be held by the Florida Department of Corrections. You also can enter this information into that agency's website, available through The Inmate Locator database.
Learn the procedures specific to the institution in which the inmate is held. Every facility and jurisdiction has its own policies about contacting an inmate. Most list their procedures on their websites, but some will supply them only over the phone.
Write a letter to the inmate. Most inmates can receive written letters. Usually, the letter must be addressed to the inmate using his name, inmate number and the the name of the facility in which he is being housed. Most state prisoners are not allowed to send or receive email, but some federal prisoners are given limited email access.
Try to arrange a phone call. Almost all inmates are unable to receive incoming calls, but you may be able to arrange to have the inmate call you by providing your name and telephone number. Inmates are often allowed a short list of people whom they are authorized to call. Calls are usually limited in duration.
Try to arrange a visit. Many inmates are allowed visiting privileges, so you can also contact them in person. The hours and conditions of visits vary by institution. Often, both the warden and the inmate will have to approve your visit beforehand.