Schwalger was suspended by the Lakapi Samoa Board last year after serious criminal charges were filed against him.
He was charged with unlawful sexual connection, attempted sexual violation, sexual conduct with a person under 16, indecent assault and common assault.
“The resignation follows a period of suspension granted to Mase following the filing of criminal charges against him in court,” Lakapi Samoa said.
Lakapi Samoa Chairman, Tuilaepa Dr Sailele Malielegaoi, expressed gratitude for Mase’s service.
“Mase has given everything to our country through the Manu Samoa, and his contributions to the team and our rugby community will always be acknowledged. His leadership has been a key part of our journey, and we wish him all the best.”
Lakapi Samoa will begin the search for a new head coach and remains committed to ensuring that Manu Samoa continues to grow and succeed at the highest levels of international rugby.
Mase, a former Manu Samoa captain, also represented New Zealand Super Rugby franchises the Highlanders, Hurricanes, and the Chiefs.
The hearing for his case has been set for April 28, and he remains under bail conditions.