Harrisburg has played in the Eastern League since 1987 and has been an affiliate of the franchise since it signed on with Montreal in 1991.
"We are delighted to once again continue our relationship with the Harrisburg Senators," said Nationals president Stan Kasten. "Harrisburg, Metro Bank Park, the Senators and their fans have served as wonderful hosts for our players through the years. We look forward to introducing them to our next wave of exciting talent and continuing our longest-running Minor League affiliation."
The Senators have a 67-59 record in the league's West Division and sit in second place, leading Bowie by one game. The top two teams in each division make the Eastern League playoffs.