It will never go negative.
" To compensate for the effects of inflation, Social Security recipients usually receive an annual cost-of-living adjustment (COLA). According to parameters outlined in the Social Security Act (42 U.S.C. §415(i)), a 5.9% COLA is payable in January 2022. For a retired worker receiving the average monthly benefit amount of $1,565, the COLA will result in a $92 increase in Social Security benefits (after final rounding down to the nearest dollar for a total of $1,657). Social Security COLAs are based on changes in the Consumer Price Index for Urban Wage Earners and Clerical Workers (CPI-W), updated monthly by the Department of Labor’s Bureau of Labor Statistics (BLS). The COLA equals the growth, if any, in the index from the highest third calendar quarter average CPI-W recorded (typically, from the previous year) to the average CPIW for the third calendar quarter of the current year. The COLA becomes effective in December of the current year and is payable in January of the following year. (Social Security payments always reflect the benefits due for the preceding month.) If there is no percentage increase in the CPI-W between the measuring periods, no COLA is payable. In other words, the Social Security COLA can never be negative, and benefit levels are not reduced, even during times of a decreasing price index. No COLA was payable in January 2010, January 2011, or in January 2016. The January 2022 COLA will also be applied to Supplemental Security Income (SSI) and railroad retirement “tier 1” benefits, among other changes in the Social Security program. Although COLAs under the federal Civil Service Retirement System (CSRS) and the federal military retirement program are not triggered directly by the Social Security COLA, these programs use the same measuring period and formula for computing their COLAs."
