My PIA was $971 before WEP was applied. My non-covered pension is $778. SSA says my WEP PIA is $431 (i.e. SSA reduced my benefit by $540). I thought my reduction could not exceed 50% of my non-covered pension (i.e. $788/2=$389) based on the WEP guarantee.

RS 00605 says: Calculate the WEP PIA and round to the lower dime. Calculate a regular PIA and reduce by 50 percent of the applicable pension amount. (See RS 00605.370 for WEP Guarantee). Select the larger of RS 00605.369A.1.c. & d.

So shouldn't my benefit be $582 ($971-$389) instead of the $431 that I am currently receiving?

Hi. I can't give you a definite answer. The Windfall Elimination Provision (WEP) guarantee provisions provides that the maximum reduction to a person's primary insurance amount (PIA) that can be caused by WEP is 50% of the gross amount of the person's non-covered pension (https://secure.ssa.gov/apps10/poms.nsf/lnx/0300605370). The guarantee reduction amount is calculated based on the person's GROSS non-covered pension amount at the time of their first month of entitlement to BOTH the non-covered pension and Social Security retirement or disability benefits .

Therefore, the exact dollar amount of any WEP reduction applied to a person's benefit rate depends on a number of variables. I would suggest that you consider filing an appeal if you believe that the WEP reduction in your case has been incorrectly calculated (https://www.ssa.gov/apply/appeal-application-decision).

Best, Jerry