Active duty for the Viet Nam war was deferred when Chet was accepted to Loyola Dental School. During his junior and senior years in dental school he was vice president of Delta Sigma Delta, a professional dental fraternity. Upon graduation in 1976, Chet and his wife, Dagmar, left Chicago to fulfill his military obligation. He was stationed at Bassett Army Hospital, Ft. Wainwright, Fairbanks, Alaska, followed by Madigan Army Medical Center, Ft. Lewis, Tacoma, Washington. During the four years at Fort Lewis, besides providing dental services to the hospital staff, inpatients, and the medically compromised at the medical center, he served as company commander of the 35 dental enlisted personnel for one and a half years, and Chief of Restorative Services for three years. Chet was promoted to the rank of Major while at Ft. Lewis. Following completion of the advanced officer course at Ft Sam Houston, Chet was assigned to do primarily oral surgery in a troop clinic at Ft. Bliss, El Paso, Texas, but found himself filling in periodically for the pedodontist. While there he was also a CPR instructor and published an article in the Journal of Oral and Maxillofacial Surgery. Upon completion of his tour at Ft. Bliss he was awarded the Meritorious Service Medal, First Oak Leaf Cluster.
In 1985 Chet and Dagmar left the military and returned to Chicago. Chet joined the Dental Arts Club, the Polish dental society of Chicago in 1985, and served its president in 1996 and continues to be an Advisory Board Member. Also in 1985 Chet joined the Chicago Society Lodge of the Polish National Alliance, and for several years was chairman of the scholarship committee, and served for two years as recording secretary and two years as treasurer. Chet has served as president for five years of the Belmont-Central Unit of the American Cancer Society, and currently is president of the Chicago Graduate Chapter of Delta Sigma Delta. Also active in the Chicago Dental Society he has worked on the various committees including the Speakers committee, Registration and Credentials, and General Arrangements Committees for the Midwinter Meeting, Peer Review Committee, and was Chairman of Mediation Committee for the CDS, and President of the Northwest Side Branch. Currently he is Chairman of Mediation for the Northwest Branch of the CDS.
When the dental society elected to take a more active role in the development of dental students, Dr. Klos agreed be a mentor and was assigned a freshman. In her sophomore year he and his student decided that the best learning experience would be for her to work as his dental assistant. Three years later, having graduated as one of the top clinical students at UIC Dental School, Dr. Larisa Spirtovic joined Dr. Chet Klos as an associate at his practice at 5841 W. Belmont Avenue. In 2010 together they formed Kiss Dental PC and established the office at 2925 Touhy. In 2019 they sold the Belmont office and are now working together in the same office. Dr Chet with help from Dr Larisa continues to mentor students today.
Chet and Dagmar live on the NW side of Chicago, enjoy their dog walks through the neighboring forest preserve, and bike rides on various trails. Dagmar is actively involved in the textile community, teaching dyeing, spinning, and weaving as well as having authored The Dyers Companion published by Interweave Press.