Small Aircraft
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 6
Communication Breakdown; Confusion; Situational Awareness
ATC Issue All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Human Factors
I took over the sector from another controller. He had received coordination from ZMP that Aircraft X had requested FL065 due to unfavorable winds higher. When I took over the aircraft was non-radar and I thought the aircraft was VFR not IFR due to misinterpreting the data block. When Aircraft X came back on radar it was level at 065 entering a 070 MIA box. I was confused why it was flashing MSAW [Minimum Safe Altitude Warning] as a VFR and asked the pilot. The pilot said they were IFR so I climbed them immediately to 070 for terrain. I believe this was because it was easy to misinterpret a non-radar IFR at a VFR altitude as a VFR. When I gave a briefing to the next controller I told him the airplane behind Aircraft X; who was in a similar situation: level at 075 IFR non-radar; was IFR. Minutes after the briefing I came back and told him again just to be clear and he said 'Oh I thought he was VFR.' I should review Low Altitude Alert phraseology; it was not issued. I don't know what can be done about the easy of misinterpreting IFR non-radar assigned VFR altitudes as VFR besides either not issuing VFR altitudes or being very very clear about what is going on and making sure the next controller understands the situation.
Salt Lake Center Controller reported misinterpreting a data block which resulted in an IFR aircraft being below the minimum IFR Altitude.