Currently, the OIKAWA family name centers on the middle and southern parts of Iwate Prefecture and the northern part of Miyagi Prefecture (53％ of all OIKAWA clan live in both prefectures), but was scattered around the prefectures of the Tohoku region such as Aomori, Akita, Yamagata and Fukushima.
現在、及川という苗字は岩手県の中部南部と宮城県の北部を中心としつつも（両県合わせて全及川氏の53％）、青森・秋田・山形・福島の東北地方各県に散在している。