Zerka Moreno, the widow of psychodrama and group therapy pioneer Jacob Moreno and who continued his work and practice after his death in 1974, died Sept. 19 at a nursing home in Rockville, Md. She was 99.

The cause was congestive heart failure, said a son, Jonathan Moreno.

Mrs. Moreno, 28 years younger than her husband, was a partner with him in a psychodrama and group therapy practice in Beacon, N.Y. They established the Psychodramatic Institute in 1942 and began publishing the journal Group Psychotherapy in 1947. They began working together soon after they met in 1941.

Psychodrama therapy is a form of treatment in which individuals participate in role plays of real-life experiences, often playing themselves, sometimes family members or friends who have been affected by their behavior.

Zerka Toeman was born in Amsterdam on June 13, 1917. She attended secondary school in the Netherlands and a technical school in London before settling in the United States in 1939. She had no college or medical degree.

She met Dr. Moreno while seeking psychiatric care for a sister. In 1948 he looked up from his work one day, according to their son, turned to Ms. Toeman and said, “Let’s get married.” So they did. Then they went back to work.

Mrs. Moreno was co-founder of the International Association for Group Psychotherapy and the American Society of Group Psychotherapy and Psychodrama. She was author of dozens of books and articles and a 2012 memoir, “To Dream Again.”

At the age of 40, Mrs. Moreno was diagnosed with cancer that led to an amputation of her right arm. But she continued to work up until just before her death.

She moved to Charlottesville in 1996 and in 2013 to the nursing home in Rockville. Having suffered a broken hip, she continued to see patients from her bed at the nursing home, her son said.

Besides her son, of Washington, survivors include a stepdaughter, Regina Moreno of Berkeley, Calif.; and two grandchildren.