The going-private merger is with Insight Acquisition Corp., a unit led by Insight co-founders Sidney Knafel and Michael Willner, and affiliates of The Carlyle Group.
Holders of Insight Class A common stock and Class B common stock and the company's "disinterested" class A common stock holders voted in favor of the merger as a single class.
Following the merger, all outstanding shares of company Class A stock, other than those held by continuing investors, were converted into the right to receive $11.75 per share in cash, without interest.
Insight said its current management team will remain in place.
"Customers and employees of Insight Communications are excited about this new chapter in our corporate history, and we are determined to thrive as a private company," said Willner, Insight Communications' CEO.
Insight, the ninth largest U.S. MSO, serves 1.3 million customers. Its plan follows a similar one by Cox Communications, which went private about a year ago.