Yes, on about $36,000 a year all-in, and the thing most articles tell you about this scenario, that your 401k is frozen until 59½, is simply not true. Here's the backtested math, ladder included.
Search this question and the top results will tell you two things: that 4% of $1 million is $40,000 a year, and that your 401k is untouchable until 59½ so you'll need "alternative savings instruments." The first is incomplete and the second is just wrong, and at 40 the difference matters more than at any other age. I run a calculator that backtests this scenario against real market history with actual tax math, so here's the version with the missing pieces filled in.
| Where the money sits | At a 4% rate | At 3.5% |
|---|---|---|
| All of it in a taxable brokerage | $36,750/yr | $32,250/yr |
| $550,000 in a 401k, rest taxable, Roth ladder running | $36,250/yr | $32,000/yr |
Maximum all-in spending, including $7,000/yr for health insurance. Single filer, a flat ~5% state tax, 7% real return. Every figure links to the live calculation, so you can change any assumption.
The honest ceiling is about $36,750 a year of total spending at a 4% rate, or $32,250 at the 3.5% that better fits a retirement that has to survive five decades. Notice the second row: with $550,000 of the million locked in a 401k and a Roth conversion ladder running, the number barely moves. That's the part the "locked until 59½" articles miss. The lock has a key, and it costs less than people think.
The 10% early-withdrawal penalty is real, but the IRS provides legitimate exits, and the workhorse is the Roth conversion ladder: convert a slice of the 401k to Roth each year, pay ordinary income tax on the conversion, wait five tax years, withdraw penalty-free. Repeat annually and you've built a pipeline that starts paying out at 45 and never stops. (There's also the 72(t) route of fixed substantially-equal payments, more rigid and easier to fumble, and worth knowing exists.) The requirement that actually bites is the bridge: you need roughly five years of spending accessible in taxable accounts and cash while the first conversions season. Here that's $400,000 of brokerage plus $50,000 of cash against ~$36,250 a year of spending, which clears comfortably.
Same two leaks as every early retirement, just longer. Taxes first: the 4% rule's $40,000 is gross, and netting that much spendable requires withdrawing more, especially from the 401k side where every dollar is ordinary income. Then health insurance for twenty-five years until Medicare, which I budgeted at $7,000 a year. The quiet good news is that your premium keys off taxable income rather than spending, and a brokerage-funded life can report remarkably little income, though the 2026 return of the ACA subsidy cliff makes that math worth doing carefully. Both rabbit holes: taxes and health insurance before 65.
A 40-year-old retiree should plan for the portfolio to outlive every market regime: multiple crashes, at least one nasty inflation stretch, probably something nobody's named yet. Fixed-rate rules can't see sequence-of-returns risk, where an early crash forces you to sell cheap and cripples everything after. So the calculator doesn't check averages. It replays your exact plan from every historical starting year since the 1920s and reports whether it survived all of them, 1929 and 1973 included. For a fifty-year horizon, that's the only test I'd trust.
See this exact scenario live, then make it yoursVariants: no state income tax · California · or change anything once it loads.
Not financial advice. Consult a fee-only fiduciary CFP for personalized guidance. Tax figures use 2026 brackets.