Sigman co-founded with Daniel Geschwind the UCLA Center for Autism Research and Treatment (CART) and served as its director for much of her career. She was named Outstanding Research Mentor at the Department of Psychiatry of UCLA in 2000 in recognition of her positive impact on the lives and careers of her graduate students.
Sigman was past-president of the International Society for Autism Research (INSAR) and a Charter Fellow of the Society. In 2009, she was honored by INSAR with a Lifetime Achievement Award for her research on joint attention in autism.
Sigman was co-author with Lisa Capps of the 1997 book ''Children with Autism: A Developmental Perspective''. The book emphasized the importance of a developmental perspective for understanding autism, and contrasted behaviors of children with and without autism across different developmental stages.