It is easy to assume Social Security works like a pension with a guaranteed minimum monthly check: work long enough to qualify, retire, and receive at least a certain amount. That is not how regular Social Security retirement benefits are calculated, and two people who both qualify can receive dramatically different payments. Your benefit primarily reflects your earnings history and claiming age, while a little-understood “special minimum” provision exists only for certain longtime low-wage workers. Supplemental Security Income, or SSI, creates even more confusion because it has a federal payment standard but is a separate needs-based program. Here is what retirees need to know about the minimum Social Security benefit.