http://ssa.gov/pubs/EN-05-10007.pdfIf you receive a pension from a federal, state or local government based on work where you did not pay Social Security taxes, your Social Security spouse's or widow's or widower's benefits may be reduced.
Your Social Security benefits will be reduced by two-thirds of your government pension. In other words, if you get a monthly civil service pension of $600, two-thirds of that, or $400, must be deducted from your Social Security benefits. For example, if you are eligible for a $500 spouse's, widow's or widower's benefit from Social Security, you will receive $100 per month from Social Security ($500 - $400 = $100).