Under the policy, the leave will be for a period of seven days unless the league opts to extend it.
"Major League Baseball's Department of Investigations has commenced an investigation into the matter that led to his placement on Administrative Leave. MLB will have no further comment until the investigation is complete," MLB said in a statement.
The 27-year-old from the Dominican Republic has been one of the Yankees' top pitchers this season with an 18-4 record. The right-hander has 4.03 ERA and has racked up 153 strikeouts in 143 innings.
Germán last pitched for the Yankees on Wednesday against the Los Angeles Angels, throwing 2.1 scoreless innings in relief.
"We fully support all measures being undertaken by the Commissioner's Office pursuant to the Policy on Domestic Violence. We support this policy which reinforces that domestic violence has no place in our society and cannot be tolerated," the Yankees said in a statement.
Story is developing.