For most of a career, the advice is simple: max your 401(k), max your IRA, and put whatever's left in a taxable brokerage account. That advice is correct for building the largest possible pile of money by a traditional retirement age. It says nothing about when you can actually touch that money, and for anyone planning to retire before 59 and a half, that gap matters more than almost any other variable in the plan.
This is a different question from asset location, which is about which asset type belongs in which account for tax efficiency. This is about how much needs to sit in an account you can access on any ordinary Tuesday, versus how much can stay locked behind an age requirement, because the 2 totals solve for different problems.
The problem a maxed-out 401(k) creates
Traditional 401(k) and IRA withdrawals taken before age 59 and a half generally owe a 10% additional tax under IRC Section 72(t), stacked on top of ordinary income tax on the distribution (IRS Topic 558). There are exceptions (the Rule of 55, 72(t) substantially equal periodic payments, a handful of narrower carve-outs like disability or certain medical expenses), and our guide on bridging to 59 and a half walks through how those work. But every one of those exceptions comes with restrictions, paperwork, or a multi-year commitment, and none of them is as simple as logging into a brokerage account and selling shares.
That's the gap a taxable brokerage account fills. It has no age restriction, no early withdrawal penalty, and no formula you have to commit to for 5 years in advance. Sell, pay capital gains tax on the growth, and the cash is in your bank account within days.
The problem is that building a taxable account large enough to bridge a real gap, potentially a decade or more if you're aiming to retire well before 59 and a half, usually means consciously not sending every spare dollar into the 401(k), even past the match. That's an uncomfortable instruction for anyone who's spent years being told to max tax-advantaged space first.
Sizing the bridge: the actual math
Start from the gap you're trying to cover, not an arbitrary percentage.
Step 1: find your bridge length. Subtract your planned retirement age from 59 and a half, which is the minimum for even penalty-free IRA access under the standard rules. Someone retiring at 50 has a 9.5-year gap. Someone retiring at 55 using the Rule of 55 on their current employer's 401(k) specifically may have no gap at all for that one account, but still needs a bridge for IRA money and any 401(k) from a previous employer.
Step 2: find your annual bridge spending. This is your expected retirement spending during the bridge years, which may be lower than later retirement spending if you're not yet drawing Social Security or paying for things that change with age, but treat it as roughly equal to your steady-state number unless you have a specific reason to adjust it.
Step 3: multiply. A $70,000 annual spending need across a 9.5-year bridge is $665,000. That's the rough floor for the taxable account (or other accessible sources, including Roth contribution basis, which can always be withdrawn tax and penalty free regardless of age) by the time the bridge years start.
A worked example. Priya is 35, plans to retire at 50, and expects to need $80,000 a year. Her bridge is 9.5 years, so her target accessible balance at 50 is $760,000. She currently has $180,000 in a 401(k), $40,000 in a Roth IRA (of which $28,000 is contributions, meaning that much is always withdrawable), and $95,000 in a taxable brokerage account. Her current accessible total, counting only the Roth contribution basis and the full taxable balance, is $123,000. Over the next 15 years, she needs that accessible pile, growing with contributions and returns, to reach $760,000, which means directing new savings toward taxable and Roth contributions more heavily than a max-401(k)-first approach would, even though the 401(k) alone would produce a larger total number by 50.
Why maxing the 401(k) first can work against this goal
The standard order-of-operations advice (match, then max tax-advantaged space, then taxable) optimizes for total wealth at a traditional retirement age, because tax-deferred growth compounds without an annual tax drag. For someone retiring at 65, that's close to the right call with few exceptions.
For someone retiring at 45 or 50, the same advice can produce a portfolio that looks enormous on a net worth dashboard and is still mostly inaccessible for over a decade. A poster on an early-retirement forum summarized the realization plainly: after years of maxing tax-advantaged accounts, they found themselves with roughly 95% of savings in IRAs and had to deliberately redirect new contributions toward a taxable bridge instead, pulling back to just the employer match in the 401(k) for a stretch.
That's not an argument against tax-advantaged accounts. It's an argument for sequencing: once your taxable and Roth-contribution bridge is sized to cover the gap, redirecting toward tax-advantaged space again is reasonable. The mistake is maxing tax-advantaged accounts on autopilot for 20 years and discovering the bridge problem at 48.
What counts as "accessible" for this calculation
Be precise here, because being generous with what counts as liquid defeats the purpose of the exercise.
Counts in full: taxable brokerage balances, high-yield savings, and any Roth IRA contribution basis (not earnings, and not converted amounts unless the 5-year clock on that specific conversion has passed).
Counts with friction: a 72(t) SEPP election works, but it locks you into a fixed annual distribution schedule for 5 years or until 59 and a half, whichever is longer, and deviating from the schedule retroactively applies the 10% penalty to everything you've withdrawn. The Rule of 55 only covers the 401(k) at the employer you separated from in or after the year you turned 55, not IRAs or old 401(k)s from prior jobs.
Doesn't count: home equity, unless you have a specific, costed plan to access it (a HELOC is a loan, not income, and shouldn't be treated as an emergency fund any more than it should be treated as a bridge).
A rule of thumb, held loosely
Financial independence writers have floated targets like building after-tax holdings to roughly match pre-tax balances by around age 30 for people planning an early exit, as a way of forcing the bridge-building habit before the gap becomes urgent. Treat that as a directional nudge, not a rule. The real target is always your specific bridge length times your specific spending need, recalculated every few years as both numbers change.
If you're tracking retirement and taxable accounts side by side in Steady Wealth, you can see the accessible total versus the locked total directly, rather than estimating the split from memory or an old spreadsheet.
Frequently asked questions
Should I stop contributing to my 401(k) to build a taxable bridge?
Not entirely. Keep contributing enough to get the full employer match, since that's an immediate return no bridge math outweighs. Beyond the match, the right split depends on how large your bridge gap is relative to how many working years you have left to close it. A large gap with few years left to build it justifies weighting new contributions toward taxable and Roth basis for a while.
Does a Roth IRA help with the bridge, or is it locked like a 401(k)?
It helps more than people expect. Contributions (the money you put in, not the earnings) can be withdrawn at any time, for any reason, with no tax and no penalty, because you already paid tax on that money before contributing it. Only the earnings and converted balances carry age and holding-period restrictions.
What's the penalty for taking 401(k) or IRA money out early without an exception?
A 10% additional tax on the taxable portion of the withdrawal, on top of ordinary income tax, under IRC Section 72(t)(1) (IRS Topic 558). The income tax applies regardless of age; the 10% is specifically for taking it before 59 and a half without qualifying for an exception.
Is there a downside to having too much in taxable accounts?
Yes. Taxable accounts lose the tax-deferred or tax-free compounding that retirement accounts offer, and you owe capital gains tax on growth along the way. The goal isn't to maximize taxable holdings generally, only to size them (plus accessible Roth basis) to cover the specific gap between your planned retirement age and 59 and a half.