Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 5
Communication Breakdown; Distraction
ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued New Clearance; Air Traffic Control Issued Advisory / Alert; Flight Crew Returned To Clearance
Procedure; Human Factors
Aircraft X was IAFDOF (Inappropriate Altitude for Direction of Flight) at 120 eastbound and there was traffic opposite direction at 120. I had addressed the situation with the R-side who had just sat down. The MIA (Minimum IFR Altitude) in the area was 110. The decision was made to descend Aircraft X to 110. I am not sure if I was on the line coordinating or working on another situation but I did not hear the clearance to descend nor the read back but Aircraft X descended below 110 and was through 106 when the R-side verified the altitude restriction. Aircraft X was issued a clearance to climb and maintain 110 which he stated he thought the original clearance was to 100.
ZLC Controller reported a PA28 descended below Minimum Vectoring Altitude.