Kagan grew up in a family of renowned architects and designers. He studied architecture at Columbia University before turning to furniture design. In the 1940s and 1950s, he worked in his family's New York business, which manufactured modern furniture.
In the 1950s, Kagan began creating his own designs and quickly gained a reputation for his sculptural, organic furniture, often inspired by nature and the human body. His work became very popular with celebrities and high-end clients.
Over the decades, Kagan has developed a range of lounge furniture, chairs, sofas and dining tables that have been acclaimed for their comfort, elegance and originality. He has also worked on interior design projects for hotels, restaurants and public spaces.
Kagan has received numerous awards for his work, including the Industrial Design Award from the Institute of Business Designers in 1979 and the Outstanding Contribution to the Profession Award from the American Society of Interior Designers in 2004. His work is exhibited in museums such as London's Victoria and Albert Museum and New York's Museum of Arts and Design.