Extent of hypothyroidism. For life?

My prospective partner (41 years) says he has hypothyroidism and will be taking medicine lifelong. He is currently on Thyronorm 25 mg. He says it is genetic with half his family having the condition. Report of his test taken in 2015 shows T3 & T4 within range, but TSH is 5.62, though range is 0.35 - 5.5. Latest report results (Jan 2017) are: T3 C.L.I.A 110 ng/dl 60 - 200 T4 C.L.I.A 9.2 μg/dl 4.5 - 12 TSH C.L.I.A 3.68 μIU/ml 0.3 - 5.5 Comments : SUGGESTING THYRONORMALCY Please correlate with clinical conditions. Since the 2015 report shows that TSH value is out of range only subclinically, why does he have to take medicine all his life? Could it be that he has not shared all the reports, and is sharing only those which show near-normal/normal results? In other words, at what levels of TSH is the condition called hypothyroidism and thyronorm is prescribed for life?