Despite cost-of-living increases, rising obligations, such as Medicare premiums, can cut into Social Security benefits for retirees, according to recent research. The study found that the COLA applied to benefits does not typically keep up with Medicare payment adjustments. Also, the income levels above which benefits are taxed have not been raised to match price and income growth. As of the July consumer price index data, the program’s COLA is estimated to be 6.2%, the highest in some 40 years. While benefits are typically increased each year, so are Medicare premiums.