Reinhard IV was born the son of Philipp I, Count of Hanau-Münzenberg and his wife, Countess Adriana of Nassau-Siegen (1449–1477).

Reinhard IV made several journeys in his youth: in 1493 to the Palatine court at Heidelberg and in 1495 to the Diet of Worms.

In 1500, Reinhard exchanged some territories with the County of Isenburg, giving them Offenbach am Main and his share of Bracht and received the village of Bischofsheim (now part of Maintal) in return, thereby ending a protracted conflict between the two neighboring rulers.

In 1503, he exchanged half the village of Trais (now part of Münzenberg) for the share in Seckbach held by the Counts of Solms.

His most prominent opponent may have been Götz von Berlichingen, who raided a convoy in the Kinzig valley which was protected by Reinhard's troops.