We all know that low- and middle-income workers generally don't have enough saved for retirement.
Richer folks, it turns out, might be in the same boat.
That's the takeaway from a new study by economists at the Schwartz Center for Economic Policy Analysis at the New School for Social Research.
"We always knew the bottom and the top were different and that they were growing apart," said Teresa Ghilarducci, an economics professor at the New School for Social Research and a co-author of the report. "But we were surprised that our retirement system creates winners and losers even within the same class of workers."
The researchers tracked the retirement savings of people ages 51 to 56, using the Health and Retirement Study and IRS tax data. The project took two years.
The authors found a great range in preparedness levels among people in the top-fifth of the earnings distribution, suggesting that even many prosperous Americans could struggle financially as they climb up the decades in age.
Around 30% of people ages 51 to 56 who earn more than $80,000 a year have less than $200,000 saved for retirement, while 15% have more than $700,000.
Just 3% have reached the $1 million savings goal suggested by experts.
"Even the top earners don't have as much as you'd expect them to have," said Siavash Radpour, a research associate at the New School for Social Research and another author on the study.
To be sure, the situation is much worse for low-income Americans.
Half of retirement wealth in the U.S. is concentrated among workers who earn more than $80,000 a year. Those who earn less than $25,000 a year, in comparison, hold just 1% of that wealth.
And that imbalance is worsening: In 2010, 51% of Americans who made less than $25,000 a year had no retirement savings, up from 45% in 1992.
Still, the research shows that income goes only so far in determining the health of a person's retirement savings. That balance hangs on many other factors, including whether or not your job offers you a 401(k), which assets your employer selects and if you took breaks from the workforce. (More than 40% of millennials don't have access to a retirement plan through their job, according to Pew Trusts).
"There's so much arbitrary stuff involved," Ghilarducci said. "It's not just whether you're high-income, low-income or middle-income."
Back in the 1980s, she said, 401(k) plans were framed as a comprehensive solution to the shortcomings of Social Security.
However, the researchers found that median retirement wealth falls 84% short of what people would accumulate if they saved 6% of every paycheck with a 50% employer match.
The authors recommend that lawmakers bolster Social Security and consider "guaranteed retirement accounts," in which people save in low-fee accounts with modest returns and then are later paid out in regular installments.
"We've run the experiment for 40 years," Ghilarducci said. "We pronounce it a failure."