Final answer:
In October 2007, CMS implemented the MS-DRG system to adjust payments based on the severity of a patient's condition and the required treatment resources, providing for a more fair reimbursement to hospitals.
Step-by-step explanation:
In October 2007, CMS (Centers for Medicare & Medicaid Services) implemented the MS-DRG system, which stands for Medicare Severity Diagnosis Related Groups. This system was designed to better reflect the severity of a patient's condition and the resources required to treat them. Instead of the flat-rate per case payment system, MS-DRGs adjust payments based on various factors, including severity of illness, the costliness of the treatment, and the resources needed. This was a significant change in the way hospitals were reimbursed for treating Medicare patients and it aimed to provide a more accurate and fair payment system.