The archdiocese announced this on Friday.
The mergers will start in 2028.
Management, finance and personnel are being reorganized.
The reason for the structural reform is, among other things, the decline in church members, priests and volunteers.
"In addition, the abuse scandal in particular has led to a massive loss of trust in the institution of the Church," according to the archdiocese. Even now, reliable pastoral care can no longer be ensured everywhere.
Church life continues in communities
The Archdiocese plans that the previous deans – with two exceptions – will become the future 21 pastoral rooms. Each pastoral room usually corresponds to a parish.
The new units will be led by teams of three, to whom at least one priest must belong, according to church law. In addition to the management team, there should be a full-time position for commitment promotion in every pastoral care room.
The Archdiocese emphasized that the pastoral care area is not the level on which all church life will take place in the future.
"The church continues to live where people pray, celebrate worship, accompany each other, help, alleviate hardship, experience community and take responsibility: in communities, churches, facilities, groups and initiatives," said the two Vicar General Michael Bredeck and Thomas Dornseifer.
Together with the parishes, the diocese administration will also be restructured.
The reforms are the result of an approximately one-year consultation process, in which church members and various committees were also involved.
The Archdiocese of Paderborn has 1.25 million Catholics.