He previously served as the defensive backs coach at Purdue under Joe Tiller and Danny Hope from 2004 to 2011, the Miami Dolphins from 2012 to 2017, and the New York Giants in 2018.
[9][10] On October 8, 2015, he was chosen to be the interim defensive coordinator of the Miami Dolphins to replace Kevin Coyle who was fired the same day.
[13] On February 21, 2019, Anarumo was hired by the Cincinnati Bengals as their defensive coordinator under head coach Zac Taylor.
[15][16] In the 2021–22 AFC Championship Game, Anarumo's defense held the Kansas City Chiefs to just a field goal in the second half and forced an interception in overtime, contributing to a 27–24 OT victory to advance to Super Bowl LVI.
[18] During the 2023 offseason, Lou Anarumo was a finalist for the Arizona Cardinals head coaching job that ultimately went to Jonathan Gannon.