In order to elicit information necessary to determine whether and by how much a foreign
pension may reduce a worker's benefit, SSA has had to rely on Form SSA-150, Modified
Benefit Formula Questionnaire (see RS 00605.390). However, since this form was designed primarily to capture information about Civil
Service pensions, it is inadequate when used to elicit information about a foreign
pension. For example, pensions from countries with which the United States has concluded
an international Social Security (or “totalization”) agreement (see GN 01700.000) may or may not be used to reduce the U.S. Social Security benefit, depending upon
whether a regular benefit or a totalization benefit is payable (see GN 01701.300). Therefore, SSA has devised a new form; i.e., form SSA-308, to be used specifically
for developing WEP cases where a foreign pension is involved. (A separate SSA-308
should be obtained for each foreign pension payable.)