The average life expectancy has declined in all 50 states and Washington, D.C., and Texas was along the states reporting the biggest drops, a new study shows. Indeed, the average life expectancy in Texas slid by 3.83% from 2018 to 2021, according to Forbes Advisor analysis, ranking it as the state with 14th-largest decline during that period. As a result, the average life expectancy in the Lone Star State is now 75.4 years.