Banks want my ss number ????

There are no good banks. Some are better than others. But I'd bet my bottom dollar that EVERY bank in Costa Rica and the USA requires your social security number as long as you're still a Citizen of the USA. (Even if you're a CR citizen, you have to RENOUNCE your US Citizenship to be free of this rule, which from what I understand, is not that easy or quick to do.)

I can't imagine any bank in this day and age, in this or any other country, that doesn't require your social security number if you're an American. (Actually I think maybe Singapore doesn't... but none in North or Central America I don't think.)

This is because the US government uses "terrorism and drugs" as an excuse to know what kind of money every U.S. Citizen has in the bank, be it in the USA or other countries.

And if you have over $10k U.S. in any bank outside the USA and don't report it to the US government via IRS and/or another branch (I forget the name of the other branch of gov. that requires it), you can be subject to fines up to 100's of thousands of dollars.
https://www.irs.gov/Businesses/Comparis … quirements

So the Social Security # is the key to all this and many years ago the US government began this invasion on your privacy. Surprised you don't know about it.