In the US, concerns over such matters are virtually nonexistent.

But Spain cannot print Euros, and is already deep in the hole on meeting budget deficit targets.

Via translation from El Confidencial, Spain's Social Security Reserve Fund Exhausted by 2018.

The Social Security reserve fund will run out of money in 2018. The cause in bonus payments to pensioners, which consumes every six months (in December and July) over 8.5 billion euros. Revenue from social security contributions are not sufficient to meet the payment obligations.

Starting in 2018, only an extraordinary contribution by the State would make it possible for Social Security can meet its commitments.