May’s Supplemental Security Income payment, worth up to $967, will go out to millions of beneficiaries in 15 days. The next SSI payments are scheduled to be distributed on May 1. SSI payments are given to people living with debilitating disabilities that affect their income,

Social Security is based on lifetime earnings. The first step in calculating retired-worker benefits is adjusting (or indexing) earnings to account for changes in general wage levels over time. Doing so ensures retirement benefits reflect any increase in living standards realized while the worker was employed.

The amount of monthly benefit change will vary greatly, according to the Social Security Administration. Depending on factors such as the type of Social Security benefit received and the amount of the person’s pension, the increase will amount to “very little” to more than $1,000 each month, the agency said.