Per the Pew Research Center study back in April of this year, there were approximately 162 million workers in the US workforce. Of that amount, currently, 1/3 of the workforce consists of Millennials (born 1981-1999), at about 56 million. Gen Xers (born 1965-1981) are the next largest group, also about 1/3, at 53 million, and Boomers (born 1946-1965) are the rapidly declining element of the work force at 41 million or 25% of the workforce. Amazingly, 9 million workers age 72 or older continue to work (5%) and 3 million Post-Millennials (Generation Z, born 1999-2015) have already entered the workforce (2%), and this number grows daily.
Boomers seem to be retiring from the workforce by about 4 million per year while Millennials appear to be increasing by about 3 million per year. Gen Xers appear to be maintaining their population in the workforce. Post-Millennials (Generation Z) seem to be entering the workforce at a rate of 3 million per year. As a quick study, Generation Z is a bit smaller than Millennials (74 million to 79 million). Generation Z and Millennials will continue to grow due to immigration. So the ratios should stay the same. Notice that more than 70% of Millennials are now in the workforce. Boomers peak participation rate was just under 85% back in 1996 during the Dot.com bubble. If Millennials are like Boomers then we can expect the group to peak in about 3 years, and the economy to keep humming well into the 2020s.