While his early nonfiction books veered from psychology (The Name Game) to true crime (The Serpent's Tooth) to art collecting (The Best of Everything, with former Sotheby's chairman John L. Marion), he is best known for his controversial biographies.
In November 2008, NBC's Brian Williams presented Andersen with a Joan's Legacy Award for excellence in journalism regarding lung cancer, along with Ladies Home Journal, which excerpted the portion of his book Somewhere in Heaven: The Remarkable Love Story of Dana and Christopher Reeve describing Dana Reeve's battle with lung cancer.
[4] Andersen has made frequent appearances on TV programs such as the Today Show, Good Morning America, Entertainment Tonight, Larry King Live, The CBS Early Show, Dateline, Extra, The O'Reilly Factor, NBC Nightly News, ABC World News, 48 Hours, Inside Edition, Anderson Cooper 360 and Hardball.
Of the sequel, Jackie After Jack: Portrait of The Lady, USA Today said "readers will be spellbound" while Newsweek called the book "poignant" and "intimate".
In a lengthy 1999 Salon review, Jake Tapper wrote of Bill and Hillary: The Marriage: "Andersen dishes like a catty high school girl holding forth in the lunchroom."
Terry Hartle of the Christian Science Monitor wrote that Andersen's These Few Precious Days: The Last Year of Jack with Jackie was "fascinating and insightful" and Kirkus Reviews determined that The Good Sonwas "sensitive and astute, intimate" with "the power to mesmerize".