Montgomery County Detention Center
Montgomery County Detention Center
County Detention CenterMailing Address
[Inmate Full Name] — [Inmate ID]
Montgomery County Detention Center
P.O. Box 247, Phoenix, MD 21131
Montgomery County Detention Center
P.O. Box 247, Phoenix, MD 21131
Physical Address
1307 Seven Locks Road, Rockville, MD 20854
Governing Agency
Montgomery County Department of Correction and Rehabilitation
Inmate ID
Inmate / Booking Number — Not required
Last Verified
September 27, 2026
Facility Mailing and Service Information
Ordinary personal mail is routed through the current off-site processing address at P.O. Box 247, Phoenix, MD 21131. Use the inmate's full legal name and ID and include a complete sender return address. Legal/direct-facility mail may use the physical facility address: 1307 Seven Locks Road, Rockville, MD 20854.
Last verified: September 27, 2026
Photographs are subject to the off-site mail provider's scanning/content rules.
Last verified: September 27, 2026
Books/publications generally follow separate direct-publisher or direct-facility procedures.
Last verified: September 27, 2026
Do not send cash through ordinary off-site mail. Use the facility's approved deposit method.
Last verified: September 27, 2026
Verify current custody/placement, visitor approval requirements and current visitation rules before traveling.
Last verified: September 27, 2026
How to Address Your Letter
Ordinary personal mail is routed through the current off-site processing address at P.O. Box 247, Phoenix, MD 21131. Use the inmate's full legal name and ID and include a complete sender return address. Legal/direct-facility mail may use the physical facility address: 1307 Seven Locks Road, Rockville, MD 20854.
About Montgomery County Detention Center
Montgomery County Detention Center is a Maryland county, juvenile, corrections or auxiliary facility record reviewed for current status and mail routing on 2026-09-27.