With more retirees around the world responsible for their own financial security, the countries that ranked the best benefited from a combination of strong social programs, widely accessible health care and low levels of income inequality, according to Natixis.
Recent public spending in top-ranked Norway has bolstered the nation's pension plans, helped in part by the country's massive sovereign wealth fund. Other high-ranked countries, such as New Zealand and Australia, have universal, mandatory retirement savings plans.
Meanwhile, the United States slipped three spots to 17th for retirement security, according to the report.
Despite high per-capita income, stable financial institutions, low inflation, low unemployment and clean air, the U.S. also has one of the highest levels of income inequality among developed nations and a growing ratio of retirees to employment-age adults, which means there are fewer workers to support programs such as Social Security and Medicare.