A spokesperson for the Chief Medical Examiner's Office in Farmington, Connecticut, confirms to ET that Philbin died from a myocardial infarction due to coronary artery disease.
At the time of his death, Philbin's family released a public statement, saying, "We are deeply saddened to share that our beloved Regis Philbin passed away last night of natural causes, one month shy of his 89th birthday. His family and friends are forever grateful for the time we got to spend with him – for his warmth, his legendary sense of humor, and his singular ability to make every day into something worth talking about. We thank his fans and admirers for their incredible support over his 60-year career and ask for privacy as we mourn his loss."
Philbin was best known for his work as a host on Live! With Regis and Kelly, Who Wants to Be a Millionaire, America's Got Talent and more. He is survived by his wife, Joy, four children, and grandchildren.
In the days following his death, many stars have paid tribute including his longtime co-hosts, Kelly Ripa and Kathie Lee Gifford. Watch the clip below for more: