Marcasiano is the president of her eponymous design company in New York City. She has designed clothing and accessories, under her own brand and for other prestigious fashion companies since 1978. Marcasiano is a graduate of the Parsons School of Design/The New School and the recipient of the Cartier, DuPont, Cutty Sark and Wool Knit Awards and a member of the CFDA since 1979. Marcasiano has licensed her designs to Ben Kahn Furs, Italo Colombo shoes, Otto Grun Jewelry and been a design consultant for Joan Vass, Cole Haan, Malo Tricot and Saks Fifth Avenue.