Lefens’ paintings have been exhibited extensively in New York city, including shows at Brooke Alexander Gallery , Farah Damji Gallery , the Judith Klein Gallery and the 426 West Broadway Gallery. He also had a long-running two-person show with Walter Darby Bannard at the Ellarslie Museum.

Juried exhibitions include those curated by John Wilmerding, Chief Curator, National Museum of Art Washington DC, and another juried by Lucey Lippert, Curator, Whitney Museum, NYC

Lefens is the recipient of The Pollock-Krasner Award for Painting.

The book Lefens wrote concerning the power of pure abstraction: ‘Flying Colors’, awarded 'Today's Best Nonfiction, was published by Beacon Press, Blackstone Audiobooks and Culture and Technology Press in Bejing.
 
Press covering Lefens include Art News, American Artist, the New York Times, People Magazine, American Voices with Bill Bradley, CBS Evening news Eye on America, the Miami herald, PBS, CNN and American Profiles. 

His key mentors include the pre-eminent art critic/writer Clement Greenberg and the painter Roy Lichtenstein, with whom he had a thirty-five year friendship, and art historian Sam Hunter, Prof. Emeritus Princeton University and the author of ‘Modern Art’.

Lefens received his BFA from Virginia Commonwealth University and did graduate work at Rutgers University Mason Gross School of the Arts.