Joan P. Koser, 60 of Sioux City, passed away Saturday, May 23, 2026, in Sioux City, Iowa after a courageous battle with cancer. Visitation will be 5:00 to 7:00 P.M. with Vigil at 7:00 P.M. Tuesday, June 2, 2026, at Meyer Brothers Colonial Chapel. A Memorial Mass will be 10:30 A.M. Wednesday, June 3, 2026, at St. Michael Catholic Church in Sioux City, Iowa.

Joan was born on March 5, 1966, in Sioux City, Iowa to Edward and Pat (Lynch) Mari. She attended Bishop Heelan High School and graduated in 1984. Joan then went on to study radiology and graduated from Marian Health in 1988. In 1990, Joan married Jim Koser at St. Patrick’s Church in Jackson, Nebraska. She worked at Mercy Hospital for 38+ years as an MRI tech, where she gained many lifelong friends.

Joan enjoyed gardening and reading, and she loved spending time with her grandchildren and grand-pups. She especially loved going to the apple orchard, the zoo, and taking her grandchildren to all the local parks. She took great pride in caring for her home and treasured every moment shared with family and friends.

She is survived by her husband, Jim Koser; her children, Karissa Koser and Nate (Lindsey) Koser and their children, Logan and Jackson; siblings, Gene (Tami) Mari, Joe (Sandy) Mari, Mona(Wade) Reid, and Bob (Robin) Mari; In-laws Bev (Brian) O’Hara, Judy Cheever, and Lisa (Randy) Porsch; along with many nieces, nephews, relatives, and friends.

She was preceded in death by her parents Ed & Pat Mari; in-laws Leroy and Helen Koser; and several beloved aunts and uncles.

Namaste