401(k) vs IRA vs taxable brokerage: where should your next dollar go?

You have money to invest and three main places to put it: your workplace 401(k), an IRA you open yourself, and an ordinary taxable brokerage account. They are not a menu to pick one from — they are a waterfall to fill in order. Each account has a specific advantage and a specific limit, and the smart move is to pour your next dollar into the highest-value bucket that still has room. Here is that order, and why it goes the way it does.

Step 1: the 401(k) match — the only guaranteed return in investing

If your employer matches 401(k) contributions, that match is the first and most important stop, full stop. A dollar-for-dollar match is an instant 100% return on your money before the market does anything — no investment anywhere offers that. Contributing enough to capture the entire match is the closest thing to free money in personal finance, and skipping it is the single most common expensive mistake employees make. Whatever percentage unlocks the full match, contribute at least that. Nothing else on this list competes with it.

Step 2: max the IRA — your best-controlled account

Once the match is secured, the next dollar usually goes to an IRA rather than back into the 401(k). Why? Because an IRA is the account you control completely: you choose the provider, so you get access to the widest universe of low-cost index funds, instead of being stuck with your employer's limited (and sometimes pricey) menu. A Roth IRA in particular offers tax-free growth and tax-free withdrawals in retirement, which is extraordinarily valuable — especially for younger or lower-bracket savers who can pay the tax now at a low rate.

The tradeoff is a relatively low annual contribution limit, and higher earners face income limits on direct Roth contributions. But within that cap, the combination of full control, low costs, and tax-free growth makes the IRA the best-quality account most people have access to. Fill it every year you can, and treat the annual deadline as real — unlike a 401(k), IRA contribution room does not roll forward, so a year you skip is a year of tax-free growth you never get back.

Step 3: back to the 401(k) for the big limit

Maxed the IRA and still have money to invest? Return to the 401(k) and keep contributing beyond the match, up to its much higher annual limit. You give up the wide fund selection of an IRA, but you gain a large tax-advantaged bucket that shelters far more money than an IRA can. For high savers, this step is where the bulk of tax-advantaged accumulation actually happens, because the 401(k) limit dwarfs the IRA limit.

Step 4: the taxable brokerage — unlimited and flexible

Only after the tax-advantaged accounts are full does the ordinary taxable brokerage account earn your next dollar. It has no contribution limit and no early-withdrawal penalties, so it is where money goes once the sheltered buckets are maxed, and it doubles as the right home for money you may need before retirement age. It lacks a tax shelter, so you owe tax on dividends and gains — but held in low-cost, tax-efficient index funds, that drag is modest, and the flexibility is genuine. For most people it is step four, not step one.

One nuance worth flagging: the waterfall is about priority, not exclusivity. A taxable account is not a lesser or optional account — for anyone pursuing early retirement or a big goal before age 59, it is essential, because it is the only bucket you can tap freely without penalty. The point of the ordering is simply that when a dollar could go into either a sheltered account with room or a taxable one, the sheltered account almost always wins. Once the sheltered buckets are full, the taxable account is not a consolation prize; it is the workhorse that funds the years the retirement accounts cannot reach.

The bottom line

The order is what matters: capture the full employer match first because it is a guaranteed return nothing can beat, then fill an IRA for its control and tax-free growth, then load the rest into the 401(k) for its large limit, and finally use a taxable account for anything beyond that or for money you will need early. Pour your next dollar into the highest bucket with room left, and let the tax code do the quiet work of turning the same savings into meaningfully more retirement.