In 2005 a retrospective of his work was presented at the Smithsonian's National Museum of the American Indian in New York.  Noteworthy group shows including Mr. Martinez's paintings include "Who Stole the Tee Pee?" held at the National Museum of the American Indian in New York and "AlienNation" at the American Indian Community House Gallery.  Martinez was one of the first non-Japanese artists to be invited to exhibit at the Contemporary Artists Federation Group Sow at the Museum of Modern Art in Saitama, Japan in 2002. 

Martinez was the invited Artist at the Eiteljorg Museum November 13, 2015 - February 14, 2016.  In 2014-2015 he was given the Robert Rauschenberg residency in Captiva, Florida, whereas a year earlier he was chosen the CALL artist by the Joan Mitchell Foundation in New York City.   Martinez is one of over 30 artists whose work is exhibited at the Smithsonian's Museum of the American Indian in New York City in a show titled Stretching the Canvas Eight Decades of Native painting.  Paintings on view date from as early as 1940 to present day.  A video covering Stretching the Canvas"  Eight Decades of Native Painting , an exhibition held at the National Museum of the American Indian is available for viewing https://watch.thirteen.org/video/nyc-arts-choice-stretching-canvas-26lior/ . 

His latest New York Gallery representation takes place at the Garth Greenan Gallery, amidst a diverse group of highly significant artists.

First American Art magazine published an in-depth article on Martinez in its Spring 2021 issue.