Narrative:

Aircraft X departed cut VFR. Called airborne asking for IFR to bil. I issued squawk. Noticed aircraft filed alt FL080. Mia [is] FL093. I asked pilot if he would be able [to get to] FL100 as a final altitude due to mia [minimum IFR altitude]. He responded negative and that he was IMC climbing through FL075. I instructed him to maintain VFR and reminded him he did not have an IFR clearance. I alerted the flm [front line manager]. I was given a D side.aircraft X descended to FL073 and said he was trying to stay VFR. I asked if he could see the ground. He said yes and there was a cloud layer at FL076. I called rca approach; whose airspace he was in to see if they had a lower MVA [minimum vectoring altitude] that would help. They did not. I asked pilot if he would be able to maintain terrain obstruction clearance and climb to FL093. He said negative. I asked intentions. He said he'd try to stay VFR until I could give him a clearance. I suggested he turn back to his departure airport. He said he thought he could stay VFR.I told him the general direction and altitudes of the mia's that we're going to stair step down to the west as he flew out of the black hills. I explained what those meant in relation to the ground or obstacles. He descended to FL071. I suggested a course due west that would get him to lower terrain quicker if he could maintain VFR on that heading. He said he would. He asked about mountains and I re-explained the area terrain. He asked about the mia that was no factor and I responded. He crossed the boundary into my FL090 mia and was at FL073 so I knew he was above terrain and obstacles in that area. I [tried to advise for the pilot] and issued him an IFR clearance with a climb to 9;000 [feet]. He complied.the pilot called in and the flm made sure he understood VFR flight rules.

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Original NASA ASRS Text

Title: ZDV Center Controller reported an aircraft departing VFR; needing IFR; and entering a lower Minimum IFR Altitude area.

Narrative: Aircraft X departed CUT VFR. Called airborne asking for IFR to BIL. I issued squawk. Noticed aircraft filed alt FL080. MIA [is] FL093. I asked pilot if he would be able [to get to] FL100 as a final altitude due to MIA [Minimum IFR Altitude]. He responded negative and that he was IMC climbing through FL075. I instructed him to maintain VFR and reminded him he did not have an IFR clearance. I alerted the FLM [Front Line Manager]. I was given a D side.Aircraft X descended to FL073 and said he was trying to stay VFR. I asked if he could see the ground. He said yes and there was a cloud layer at FL076. I called RCA Approach; whose airspace he was in to see if they had a lower MVA [Minimum Vectoring Altitude] that would help. They did not. I asked pilot if he would be able to maintain terrain obstruction clearance and climb to FL093. He said negative. I asked intentions. He said he'd try to stay VFR until I could give him a clearance. I suggested he turn back to his departure airport. He said he thought he could stay VFR.I told him the general direction and altitudes of the MIA's that we're going to stair step down to the west as he flew out of the Black Hills. I explained what those meant in relation to the ground or obstacles. He descended to FL071. I suggested a course due west that would get him to lower terrain quicker if he could maintain VFR on that heading. He said he would. He asked about mountains and I re-explained the area terrain. He asked about the MIA that was no factor and I responded. He crossed the boundary into my FL090 MIA and was at FL073 so I knew he was above terrain and obstacles in that area. I [tried to advise for the pilot] and issued him an IFR clearance with a climb to 9;000 [feet]. He complied.The pilot called in and the FLM made sure he understood VFR flight rules.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.