What decade did group health insurance begin?

The concept of health insurance was proposed in 1694 by Hugh the Elder Chamberlen from the Peter Chamberlen family. In the late 19th century, "accident insurance" began to be available. Health insurance was first offered in the United States by the Franklin Health Insurance Company of Massachusetts. This fim founded in 1850, offered insurance against injuries arising from railroad and steamboat accidents. By 1866, sixty organizations were offering accident insurance, but the industry consolidated rapidly soon thereafter. While there were earlier experiments, the origins of sickness coverage in the US effectively dated from 1890. The first employer-sponsored group disability policy was issued in 1911. Hospitals and medical expense policies were introduced during the first half of the 20th century. During the 1920s, individual hospitals began offering services to individuals on a pre-paid basis, eventually leading to the development of Blue Cross organizations. The predecessors of today's Health Maintenance Organizations (HMOs) orginated beginning in 1929, through the 1930s and on during World War II.