Montserrat's first full-length play, Thoroughly Stupid Things, premiered at Manhattan Theatre Source in 2008 and was later called “a comic masterwork” by Backstage and won the Excellence in Playwriting Award at the 2008 New York International Fringe Festival.
He followed that play with Billy Carver and the Children in Mind, also at Manhattan Theatre Source which prompted Martin Denton of nytheatre.com to call him "a young artist to keep a particular eye on."
On April 5th, 2010 he formed MozzleStead with his writing partner Armistead Johnson, a television and film development company with deals in New York, Los Angeles and Austin, Texas.
In 2013 He completed work on two major motion picture screenplays. Blanco, about cocaine queen Griselda Blanco and Chisholm a film about one of his heroes, congresswoman Shirley Chisholm.