It is an increase of less than one-percent since April of 2010, which was the last time a population snapshot was taken.
That growth is at a slower pace than projected.
The Census Bureau cites low birth and immigration rates as reasons for the sluggish growth.
Now, the US population is set to be nearly 400 million by 2050.
That's short of the 439 million people projected for 2050 four years ago.