Article Snip: "...Actual pay for purposes of computing the retiree annuity supplement is only pay that is subject to retirement deductions (that is, basic pay) up to the Social Security maximum taxable wage base. (The maximum taxable wage base is the maximum amount of wages, in any calendar year, to which the Social Security tax is applied. See Table A in section 51B1.1-1.) It does not include any pay that is not subject to retirement deductions, such as cash awards or overtime (even though such pay is subject to FICA taxes) ..."
Article Resource: www.opm.gov