969.When does the included-excluded rule NOT apply?
The included-excluded rule does not apply if:
Part of your work is covered by Social Security and part by the Railroad Retirement Act;
Part of your work is performed within the U.S. for a foreign employer, and part is performed outside the U.S.; or
There is no pay period, or the pay period covers more than 31 consecutive days, or there are separate pay periods for the covered and excluded work.
In all of the above instances, the wages paid for the work covered by Social Security are counted for Social Security purposes.