How much of a worker's PIA can the spouse claim if the worker has not yet claimed their benefits?

A spouse can only claim benefits based on a worker's Primary Insurance Amount (PIA) once the worker has filed for their Social Security benefits. If the worker has not yet claimed their benefits, the spouse is not eligible to receive any spousal benefits. This is because spousal benefits are contingent upon the primary worker filing for their own retirement benefits. Therefore, the correct answer indicates that without the worker's claim, the spouse cannot access any portion of the PIA.

Understanding this rule is crucial for individuals planning retirement, as it affects their overall benefit strategy and timing.