IBM created the Shared Hospital Accounting System (SHAS) in the 1960s to address declining mainframe sales and the increased billing complexities caused by the introduction of Medicare. SHAS allowed smaller hospitals to share the large costs associated with running applications on IBM's System/360 mainframes. While SHAS was successful in automating many hospitals, its complex job control language and system bugs caused issues. SHAS also had some limitations with field sizes that could eventually be outgrown. However, it established the concept of shared systems that became more widely adopted in the healthcare industry.