Millennials have grown to make up the largest generation of Americans. Meanwhile, the number of baby boomers, which once held the title, are starting to shrink.

A review of new Census data shows differences in how these population shifts are playing out across states. Estimates published Thursday tally each state’s 2016 population by age. We’ve calculated population totals for millennials, Generation X, baby boomers, and the Silent Generation and the Greatest Generation, showing how their presence in each state has changed from 2010 through last year.



Most states are adding millennials, with the demographic’s total U.S. population increasing by about 2.6 million since 2010.

The first half of the decade saw a steady flow of millennials move into the District of Columbia, with their numbers increasing a staggering 30 percent since 2010. North Dakota recorded an increase of 18 percent, which was part of broad population gains the state experienced as a result of the energy sector boom. Colorado (+14 percent) and Washington (+9 percent) similarly saw their millennial populations climb significantly.

As a share of the total population, millennials are most prevalent in the District and Utah, the youngest state in the union. Not too far behind are Alaska (29 percent), California (28.7 percent) and Texas (28.7 percent). Gains for these and other states resulted not only from migration across state lines, but also from immigrants establishing residency.

The Census estimates suggest Mississippi is headed in the opposite direction, with a nearly 4 percent loss in millennials since 2010. Illinois, Michigan and New Mexico also saw declines exceeding 2 percent.

Definitions of the millennial generation vary. One often-cited definition by authors Neil Howe and William Strauss considers the generation to span from those born in 1982 through 2004. Others use endpoints in the mid to late 1990s. Here, we define millennials as those born between 1981 and 2000.



Generation X

Generation X makes up about one-fifth of the total population, making it the third-largest generation.

This demographic grew at the fastest rates in North Dakota (+7.7 percent) and Florida (+7.6 percent) between 2010 and 2016. Generally speaking, states that added large numbers of millennials over that period also welcomed the most Gen Xers. Just Idaho and South Carolina saw larger increases of Gen Xers than millennials.

Generation X is most concentrated in Georgia and New Jersey, where its accounts for 21.5 percent of the total population. Their numbers are fewer throughout much of the Great Plains, particularly in North Dakota and South Dakota.

The state Gen Xers left at the greatest net rate was Illinois (-4.2 percent), one of the few states registering a total population decline over the six-year period. Census estimates depict similar, but slightly smaller, losses for the District of Columbia, Mississippi and New Mexico.


Baby Boomers

Baby boomers, while still a massive bloc of the population, are no longer the nation’s largest generation. Their numbers dipped by about 3.2 million over the six-year period ending last July.

Two retirement destinations have seen the demographic expand at the fastest rates: Florida’s baby boomer population climbed 5.3 percent, while Arizona’s grew 3.3 percent. It’s worth noting, however, that the millennial population still grew at much steeper rates in both states.  The oldest baby boomers turned 70 last year, so both deaths and migration are driving population shifts. Delaware, Idaho, Nevada and South Carolina were the only other states where their numbers were still growing.

Boomers still make up more than a quarter of the population in seven states. They’re most prevalent throughout the Northeastern states of Maine, Vermont and New Hampshire.

Meanwhile, Alaska lost nearly 13 percent of its baby boomers, by far the largest decline of any state. Parts of the Mid Atlantic and Midwest also recorded sizable losses over the six-year period, with Illinois, Connecticut and New Jersey experiencing the largest percentage losses.


Silent Generation and Greatest Generation

The oldest groups of Americans, born before 1946, account for roughly 9 percent of the U.S. population.

Their numbers have fallen significantly in all states, with declines most apparent throughout the Midwest. Illinois, Ohio and Pennsylvania all recorded decreases of about 29 percent so far this decade. The largest recent declines occurred in the District of Columbia and one of the oldest states, West Virginia (-31 percent). Both deaths and migration to other states played a role in pushing down states’ totals.

Declines in this segment of older Americans were smallest in Arizona and Florida as migration to those states offset losses.


Data and Methodology

Calculations shown represent changes in population occurring between July 2010 and July 2016. The Census Bureau’s published estimates by single year of age were added for each state. Only aggregate totals are reported for those age 85 and over, so calculations for the Silent Generation and Greatest Generation were grouped together.

Reported definitions for each generation vary. Age ranges utilized for this report are similar to those used by the Pew Research Center.

Millennials: Age 16 to 35 (born 1981-2000)

Generation X: Age 36 to 51 (born 1965-1980)

Baby Boomers: Age 52 to 70 (born 1946-1964)

Silent Generation and Greatest Generation: Age 71+ (born before 1946)

This table lists calculated population estimates for each generation as of July 2016:

SOURCE: Governing calculations of Census population estimates