A person who falls under any of the following items is to be an insured for medical care for the elderly provided by the Association of Medical Care Systems for the Elderly Aged 75 and older:
次の各号のいずれかに該当する者は、後期高齢者医療広域連合が行う後期高齢者医療の被保険者とする。
a person who is 75 years of age or older and has a domicile within the area of the Association of Medical Care Systems for the Elderly Aged 75 and older;
後期高齢者医療広域連合の区域内に住所を有する七十五歳以上の者
a person who is domiciled within the district of a Association of Medical Care Systems for the Elderly Aged 75 and older and is 65 years of age or older but under 75 years of age, who has been certified by the Association of Medical Care Systems for the Elderly Aged 75 and older, pursuant to the provisions of Order of the Ministry of Health, Labour and Welfare, as being disabled to the extent specified by Cabinet Order.
後期高齢者医療広域連合の区域内に住所を有する六十五歳以上七十五歳未満の者であつて、厚生労働省令で定めるところにより、政令で定める程度の障害の状態にある旨の当該後期高齢者医療広域連合の認定を受けたもの
Read this with the articles around it