The largest inflation adjustment in 27 years will begin in January. It’s the largest increase since a 7.4 percent jump in 1982 and is more than double the 2.3 percent rise that retirees got in their monthly checks starting in January of this year. The typical retiree’s monthly check will go from $1,090 to $1,153. The average monthly check for a disabled worker will go from $1,006 to $1,064.