In 2006, Gross left Patterson and pursued a solo writing career. In 2007,
The Blue Zone debuted on the
New York Times Best Seller list in the United States. A year later, it was followed up by
The Dark Tide (2008), which the International Thriller Writers Association nominated Thriller of the Year.
The Dark Tide featured the fictional detective Ty Hauck of
Greenwich, Connecticut, who became the lead character in Gross's corruption and political conspiracy-based bestsellers ''Don't Look Twice
and Reckless''. In 2011, Gross departed from Ty Hauck, writing
Eyes Wide Open, which builds on two personal stories from his own past. January 2014, Andrew decided to bring back Ty Hauck and started writing
One Mile Under in 2015. He followed it with
The One Man, a World War II thriller, in 2016. Kirkus called the book "Gross' best work yet".
Button Man is a 2018 novel about public corruption, extortion and labor racketeering menacing the New York City garment industry during the 1930s. The novel is partly based on the life of Gross's maternal grandfather, Fred P. Pomerantz (1901–86), a garment manufacturer who stood up to mobsters such as
Lepke Buchalter,
Jacob Shapiro and
Emanuel Weiss. ==Later life and death==