India, Aug. 16 -- Social Security remains an important part of retirement income for millions of Americans. For the past 25 years, Gallup has surveyed retirees about how important Social Security is to them. The surveys have consistently found that 80% to 90% of retirees depend on their monthly Social Security payment to cover at least some of their expenses, according to Gallup. Because so many retirees rely on the money, the annual Social Security cost-of-living adjustment, or COLA, is closely watched every year. The new COLA is normally announced in October.

The COLA is an annual increase in Social Security payments. Its main purpose is to help retirees keep up with rising prices. In simple terms, if everyday goods and services become...