Forget the side hustle — welcome to the tax-shelter hustle. Solo 401(k) plans are taking off among America’s self-employed, letting freelancers sock away up to $72K a year in tax-advantaged retirement accounts — nearly 3x the employee cap for traditional workplace plans. What used to be a niche option for struggling contractors is now attracting a wealthier post-pandemic wave of DIY savers, thanks to a loophole-like feature where freelancers can contribute as both the employee and the employer.

• JPMorgan Chase and Betterment say demand is surging, with 1 in 5 Betterment advisers opening these accounts as America’s 36M mostly owner-only small businesses create a massive runway for adoption.
• Cerulli expects US retirement plans to top 1M by 2030, led by sub-$5M “micro” accounts, as Trump’s order expands retirement investing into private equity, real estate, and crypto.

The tax shelter strategy: Self-employed workers earning around $196K annually can max out a solo 401(k) at $72K by pairing a $24.5K employee deferral with a $47.5K employer contribution. That beats SEP IRAs, which offer less flexibility and no after-tax Roth option. Fintech startup Carry says solo 401(k)s have been its top product since 2022, with average balances near $50K. Many high earners in their 30s and 40s use them to unlock mega backdoor Roth contributions — though extra compliance rules kick in once balances pass $250K.