What is the average monthly cost for ADT?

ADT monitoring fees vary based on the level of coverage and special features, but monthly packages start at $36.99 per month and go up to $49.99 per month as of 2015. The more expensive packages include cellular alarm monitoring, eliminating the need to connect the system to a land line.

All of ADT's monthly packages include 24-hour monitoring, a wireless keychain remote for arming and disarming the system and high-decibel sirens, along with an infrared motion detector, a digital keypad and three door and window contacts. Several of the monthly packages also include two-way voice communication with ADT's monitoring service, allowing for hands-free connection.