MAG Partners

MAG Partners is a woman-owned real estate development firm in Manhattan, founded in 2018 by MaryAnne Gilmartin. Led by Gilmartin and her team, the company specializes in large-scale mixed-use projects, having developed over seven million square feet of office, residential and commercial space — including more than 2,000 housing units — totaling roughly $4.5 billion in value. Its New York City portfolio focuses on new rental buildings and mixed-income towers in neighborhoods such as Chelsea and Midtown. These properties typically feature modern finishes and community amenities like landscaped courtyards, fitness centers, lounge areas and rooftop terraces with gardens or pools. MAG Partners emphasizes sustainability and inclusive design: for example, one recent Chelsea development was built to Passive House standards, reflecting the firm’s focus on energy efficiency and quality of life for residents.

Besides residential rentals, MAG Partners undertakes large mixed-use and commercial projects as well. The firm is master developer of the 235-acre Baltimore Peninsula waterfront redevelopment in Maryland, and it manages more than 1.1 million square feet of New York office and retail space. One of the firm’s Manhattan projects is Ruby Chelsea at 241 West 28th Street, a 480-unit mixed-income rental tower in Chelsea. Designed by COOKFOX, this new building offers amenities including a landscaped courtyard, 24/7 concierge service, a fitness center, library and club lounges, and a rooftop pool terrace. Through properties like Ruby, MAG Partners blends market-rate and below-market housing with high-quality design and amenities, aiming to create vibrant, inclusive urban living environments.