According to a boundary description from 819, the area around today's Moosbach was assigned to the Chammünster monastery, which later founded a village with a chapel here. Moosbach itself is mentioned for the first time in the oldest Wittelsbacher Urbarbuch (1222–1228) together with some surrounding villages. Around this time the construction of a church in Moosbach also falls. In the oldest parish register of the Diocese of Regensburg from 1326 Moosbach is already listed as a parish.
Moosbach belonged to the Cham mark, was subordinate to the imperial estate district of the Reichsburg Cham and formed a border parish of the Cham deanery. When Duke Albrecht I redeemed parts of the Cham pledge, including the Moosbach parish, from Count Palatine Rupprecht on April 28, 1361, Moosbach came to the Kötzting court. In the course of the 14th century a Hofmark developed around Moosbach, which was in the hands of the Ramsbergers and came into the possession of the Nussbergers in the 14th or 15th century. On February 19, 1453 Konrad Nussberger sold the Hofmark Moosbach to Duke Albrecht III. In 1538 the sovereign "Hoffmarch Mospach" was already entered in the tax register of the Viechtach caste office. At the beginning of the 17th century the status of Moosbach was described as follows: "Hofmark, belongs with the maleficent to the Kötzting court, otherwise on the box at Viechtach"  In the years 1752/1760 there was only one main team Moosbach, which was subject to the district court Viechtach with all jurisdiction.
The municipality of Moosbach emerged in 1818 from the former municipalities of Moosbach, Rubendorf and Viechtafell. This included the former main teams Moosbach and Rubendorf as well as a considerable part of the main team Prackenbach. 1952 belonged to the municipality Moosbach in the district Viechtach 23 districts. It was incorporated into the Prackenbach community on May 1, 1978 as part of the regional reform in Bavaria.