America's 401(k) millionaires have plunged by a third

America's ranks of so-called 401(k) millionaires are diminishing following last year's stock market rout. 

The number of 401(k) accounts with at least $1 million in retirement savings fell 32% last year, to 299,000, from 442,000 in 2021, according to new data from Fidelity Investments. 

The shrinking number of 401(k) millionaires comes after the S&P 500 tumbled 19.4% last year and entered the longest bear market since the 2008 financial crisis. The downturn has marked a sharp departure from the prior decade, when a bull market buoyed investment portfolios and appeared to place a comfortable retirement within reach for many workers.

The average balance in a 401(k) plan tumbled 20.5% in 2022, reducing the typical employee nest egg to $103,900 at the end of 2022, according to Fidelity. 

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Anxieties about retirement are on the rise after last year's tough conditions, which included inflation hitting a 40-year high, experts say. One recent study found that workers now expect they will need $1.25 million for a comfortable retirement — a 20% jump from 2021.

With the decline in retirement savings, the "retirement gap" — the discrepancy between the amount of money people need to fund their golden years compared with what they've actually saved — is growing wider. And the challenge is greater when many workers are struggling to pay for basics like food and shelter, let alone plan for retirement. 

To be sure, even with the declining number of 401(k) millionaires last year, there are still more than in 2019, when there were 233,000 accounts with at least $1 million in savings, according to Fidelity. 

Notably, stashing away $1 million or more in a 401(k) plan is rare. Only about 1.4% of 401(k) accounts at the financial services firm had more than $1 million in assets at the end of 2022, according to Fidelity data.

Fidelity also noted it has seen a decline in the number of IRA accounts with at least $1 million in assets. At the end of 2022, there were 280,320 such accounts, down 25% from a year earlier.