United States - Life Expectancy at Birth, Total for Least Developed Countries was 66.51610 Number of Years in January of 2023, according to the United States Federal Reserve. Historically, United States - Life Expectancy at Birth, Total for Least Developed Countries reached a record high of 66.51610 in January of 2023 and a record low of 35.41296 in January of 1950. Trading Economics provides the current actual value, an historical data chart and related indicators for United States - Life Expectancy at Birth, Total for Least Developed Countries - last updated from the United States Federal Reserve on September of 2025.