At what altitude is an altitude reporting coded transponder required?

The requirement for an altitude reporting coded transponder is set to enhance situational awareness and safety in the National Airspace System. The correct altitude for needing this equipment is at and above 10,000 feet MSL, with the important condition that it does not apply below 2,500 feet AGL. This specific altitude range is designed to ensure that aircraft operating at higher altitudes are equipped to provide altitude data to Air Traffic Control, thereby improving tracking and separation from other aircraft.

This requirement is crucial for maintaining safe distance between various aircraft operating in busy airspaces, especially where altitude becomes critical for avoiding collisions. Operating below 2,500 feet AGL typically occurs in more controlled environments closer to the ground, where other means of separation are often sufficient. Thus, the stipulation regarding not requiring a transponder below this altitude is made to streamline the regulatory burden while still ensuring safety in the airspace structure.