Custody class can be a little complicated in TDCJ. Custody class is comprised of a two-character code, the first a letter that indicates three broad divisions, G for general population, P for safekeeping, and J for state jail housing. The second character is a number from 1 through 7. TPI mostly deals with general population and safekeeping custody levels.
G1/J1 indicates the least restrictive housing or custody level. Only G1 and J1 levels may be designated (there is no P1), and these allow housing in dorms outside the security fence and work outside the security fence.
G2/P2/J2 is sometimes called minimum security. Housing must be inside the security fence, but this is the least restrictive general classification.
G3/P3 is a minimum security classification that is only assigned to prisoners serving sentences of 50 or more years. There is no J3 custody class. G3/P3 can move to G2/P2 after 10 years.
G4/P4/J4 is a medium security classification that restricts most prisoners to living in cells rather than dorms.
G5/P5/J5 is also called close custody and is has maximum restricted movement. TDCJ claims this custody is for assaultive or aggressive prisoners, although what constitutes that assessment can be manipulated. They are confined to cells most of the day, and are to be escorted for out-of-cell movement.
P6/P7 are designations for a special protective custody or protective safekeeping. We don’t know a lot about these. P6 is a kind of minimum custody for protective safekeeping, and P7 is a kind of medium or close custody for protective safekeeping. P6/P7 are reserved for persons at extreme risk of violence inside the system, such as persons who have provided significant court testimony, persons previously employed in police and prison systems, and high-profile persons.
There are a number of things that custody level can impact, from recreation to visitation to how much one can spend on commissary. For more information, see the orientation handbook. Also available are policy documents in the TPI resources that include the TDCJ Classification Plan, Corrections Officer Manual, and other resources.