In Revenue Ruling 69-338 the Internal Revenue Service held that certain compulsory contributions levied on the salary of a U.S. citizen employee under article 66 of the Venezuelan social security law were "an income tax which is creditable within the meaning of section 901 of the Code."
Section 901 requires that in order for a foreign tax to be creditable against U.S. income tax, it must be an income tax, a war profit tax, or an excess profits tax. Section 903 expands the concept by making certain taxes imposed in lieu of income taxes also creditable against U.S. income tax.
Mack, Ronald M.
"Federal Taxation--Credit Allowed for Foreign Social Security Payments,"
Mercer Law Review: Vol. 27
, Article 11.
Available at: https://digitalcommons.law.mercer.edu/jour_mlr/vol27/iss3/11