Michael Quinn is an agent with the CIA.
Contractually.
He has declined a considerable number of offers to go work for them full-time as an official employee but each time he has respectfully demurred. He enjoys his current status with his right to turn down an assignment if it does not suit him, although to be honest he has not, apparently, actually said no as yet. The right to have that option remains which seems good enough for Quinn.
Quinn is also similarly disposed to turn down the occasional offers of commendations to be put into his record by the Special Operations Command for whom he has performed so well in the past. Quinn might be good at his job but "the anonymity and privacy of Quinn's life meant too much for him to ever change".
Quinn answers personally to the Director of the Agency but seldom at Langley. Both men prefer to have these meetings at Foxfield, the Director's secluded ranch in the Virginia countryside but it also is not uncommon for Quinn to receive an encoded message on his phone to show up impromptu mission briefings no matter where Quinn might be.
Quinn is a former Navy SEAL, having risen to the rank of Lieutenant Commander, indicating that he had served for more than a single tour. The activities we follow of Quinn for the Agency take place at least five years since leaving the military.
Prior to his service in that elite military group, Quinn had been a highly respected student in college, even earning a Rhodes Scholarship to study at Oxford before finally earning a Masters degree in Politics and International Relations.