02/09/1984
https://www.presidency.ucsb.edu...
"I transmit herewith the Agreement between the United States of America and the Portuguese Republic on Social Security."
"The Agreement was signed at Lisbon on March 30, 1988."
"The U.S.-Portugal Agreement is similar in objective to the social security agreements already in force with Belgium, Canada, the Federal Republic of Germany, Italy, Norway, Spain, Sweden, Switzerland,..."
"Such bilateral agreements provide for limited coordination between the United States and foreign social security systems to overcome the problems of gaps in protection and of dual coverage and taxatio..."