A higher percentage of children in the United States live in poverty(nearly 21%) than the population as a whole. Not only is that level of poverty unheard of in many other OECD countries, it’s unheard of that child poverty rates would be higher than overall rates. Several OECD countries have lower child poverty rates than general rates, including Denmark (2.9% vs. 5.5%), Finland (3.3% vs. 5.8%), Norway (7.7% vs. 8.2%), and Sweden (8.9% vs. 9.1%). The United States also has among the world’s highest rates of elder poverty.
As of 2010, The US Census declared 15.1% of the general population of The United States lived in poverty:
22% of all people under the age of 18
13.7% of those between the ages of 19-21
9% of all people either 65 or older [46]
Ref:
https://en.wikipedia.org/wiki/Poverty_in_the_United_States