Every piece of retirement planning advice you've ever heard tends to agree on one thing: save as much as you can, for as long as you can. Max out the 401(k). Automate it, don't touch it, and repeat for thirty to forty years.

But here's what nobody tells you: when it's okay to stop.

There is a specific number — your coast number, often called your Coast FIRE number — where your portfolio will reach your target by your retirement date without another dollar of help. Past that line, more maximum 401(k) contributions still work. They're just no longer the ideal place to put your money. And the people most likely to miss that shift are the most disciplined ones, because discipline is the habit that got them where they are.

Now, before anyone takes this out of context: this is not an article about stopping saving and living it up now. It's about what a CFP® would actually do with those dollars once you hit your coast number — and two of the three alternatives are still a form of saving, just more intentional.

If you're somewhere north of a million dollars and still grinding like you're behind, this article is for you. Let's find your coast number and give your next dollar a better job.

Milestone One: The Crossover Point (What It Tells You, and What It Doesn't)

Let's clear up the milestone people confuse with the finish line.

Somewhere on your way up, your portfolio's expected annual growth surpassed your annual contributions. To find that point, take what you save each year and divide it by your assumed return. I'll use 6% throughout as a reasonable long-run assumption for a balanced portfolio.

For a maxed-out saver contributing $32,500 a year, the math looks like this: $32,500 ÷ 0.06 = about $542,000. From there on, the market does more for your retirement in an average year than the IRS even allows you to contribute.

By $1.5 million, growth is outworking your deposits nearly three to one ($90,000 of expected growth vs. $32,500 of contributions).

But hear this clearly. The crossover point tells you who's doing the work. It does not tell you the work is done. Plenty of people cross it at $550,000 with a $2.5 million target and fifteen years of genuinely necessary saving still ahead of them.

So which number actually makes saving optional? That's milestone two.

Milestone Two: Your Coast FIRE Number

Your coast number — often called "Coast FIRE," a term borrowed from the Financial Independence, Retire Early movement — is the balance that grows into your retirement target, by your retirement date, with no further contributions at all, at an assumed average growth rate.

If your portfolio is at or past it, you can take your foot off the gas and coast from here, funding nothing but your life, and still arrive at retirement on time with enough for the rest of your life.

Meet Michael and Holly

Meet a hypothetical couple, Michael and Holly. Both are 58, living here on Oahu, with $1,500,000 invested. They're planning to retire at 63 with a $2 million target.

Let me show you the math: $2,000,000 ÷ (1.06)⁵ = $2,000,000 ÷ 1.338 = about $1,494,000.

As of this year, their plan completes itself. But that only matters if the $2 million target is actually the right target.

Your Coast Number Is Only as Good as Your Target

That's the broader point people miss with Coast FIRE: your coast number is only useful if the retirement number behind it is grounded in reality.

If you simply decide you "need $2 million" because it sounds safe, you may spend years chasing a goal you already surpassed. The target should come from the life you actually plan to fund — your spending, Social Security, taxes, other income, and the length of retirement — not from a round number that feels reassuring. That's the heart of real retirement income planning.

Morningstar's retirement income research puts a safe starting withdrawal rate around 3.9% for a 30-year retirement. On $2 million, that's about $78,000 per year of inflation-adjusted portfolio withdrawals before Social Security even begins. For Michael and Holly's actual spending needs, that provides more than enough. In other words, $2 million may already be a conservative target for them — which means their true coast number could be lower than $1.494 million.

That matters because if Michael keeps maxing his 401(k) at $32,500 a year, they'll hit $2 million in about four years instead of just under five. That's roughly $130,000 of additional saving ($32,500 × 4) to reach a target they may not even need — only about eleven months sooner.

This is the point where saving more stops being an automatic good and becomes a tradeoff. Every extra dollar going toward a retirement goal you've already secured is a dollar that could instead fund travel, reduce work, help family, improve your home, or simply make the next five years more enjoyable.

So before calculating your coast number, get the target right. Otherwise, you can do the math perfectly and still spend years coasting toward the wrong destination.

What "Optional" Actually Means: Three Better Jobs for the Next Dollar

First, the one thing that is never optional: the employer match. If your company matches the first five percent, that's an instant, guaranteed return no market offers. Contribute to the full match until your last paycheck. Everything below applies only to dollars above it.

And here's the question that should drive where the rest goes: what does a $1.5 million plan actually lack? Not more of what it already has. Michael's tax-deferred bucket is won. What his retirement is short on is flexibility, sequence protection, and the cash to run the tax strategy of his sixties.

So here's where I might recommend he redirect that money.

Job One: Fund the Life, on Purpose

Some of that money should simply be spent — the trip while parents can still travel or kids are still young, the years between 58 and 70 that carry the most health and energy you'll ever have in retirement.

Deliberate spending past your coast number isn't leakage. It's the point of the plan.

Job Two: Overbuild the Cash Bridge

The most dangerous stretch of any retirement is the first few years, when a bad market can force you to sell stocks at the bottom to pay for groceries. An oversized emergency fund plus two to three years of planned spending in cash and short-term bonds is the armor against exactly that.

Redirecting one former 401(k) year, roughly $25,000, materially deepens the bridge — and unlike another deferred contribution, it protects the sequence, not just the total.

What good is arriving at $2 million on schedule if year one forces you to sell into a crash?

Job Three: Fill the Taxable Brokerage Account

This is the underrated one. When Michael stops maxing beyond the match, the money doesn't come back as the full $32,500 — at his 24% bracket, it's about $24,700 a year after federal tax.

Five years of those redirected dollars, growing at 6%, builds roughly $139,000 in a flexible account by 63. That money has no age rules and no forced withdrawals, and it quietly makes your future tax planning better.

Why? Because the smartest way to pay for Roth conversions in your gap years is with outside cash. Convert $300,000 across your sixties at a blended 15% and the tax bill runs about $45,000 ($300,000 × 0.15). Paying it from the brokerage instead of the IRA keeps every converted dollar working.

The brokerage is also your income-control valve for health insurance subsidies before Medicare, since spending your cost basis barely shows up on a tax return.

Notice what happened. Two of the three jobs are still saving. The grind didn't stop; it got reassigned — from a tax-deferred account you've already funded to flexibility, sequence protection, and future tax capacity. The things a $1.5 million 401(k) actually lacks.

The Fair Case for Keeping the Max

Now, I want to be fair here, because coasting leans on average returns, and averages are made of good decades and bad ones.

A rough stretch right before your date can push arrival back a year or two. That's precisely why job two exists: the couple with a deep cash bridge can absorb a late start without touching stocks at the bottom, while the couple who coasted with no cushion ends up back at work.

And there are three legitimate reasons a thoughtful person keeps maxing their 401(k) anyway.

1. Tax Arbitrage

Michael defers at 24% today. If his conversion years run at a blended 15%, every dollar he pushes into that 401(k) books a nine-point spread immediately, and no cash bridge pays that well. If your bracket now is meaningfully higher than your bracket later, maxing out makes sense.

2. Your Retirement Date Isn't Set in Stone

Coasting assumes you get to choose when you stop working. A layoff at 59, a health event, a parent who needs you — any of those can pull the date forward. A coast number built on five years of growth does not survive being handed three. Extra contributions buy back some of that optionality — and that matters for anyone still asking, "When can I retire?"

3. Creditor Protection

This one almost nobody mentions. Money inside a 401(k) generally carries strong creditor protection under federal law. The same dollars in a taxable brokerage account don't. If you have real liability exposure in your work, that's not a footnote.

A Behavioral Caution

I've watched this one happen. Automation is a one-way door for a lot of people. Turning off a contribution you've made for twenty years is easy. Turning it back on is a decision you have to re-make every month, and "I'll redirect it to the brokerage" quietly becomes "I'll redirect it next quarter."

If you can't name the account the money is going to, and you haven't automated the transfer the same day you cut the 401(k), don't cut the 401(k) yet.

So the honest version isn't that coasting beats maxing out the 401(k). It's which risk you'd rather carry: paying more tax than you had to, or arriving on time with nothing liquid to arrive with.

Saving Got You to the Coast

Let's put the two numbers back in their places.

The crossover point — around $542,000 for a maxed-out saver at 6% — tells you who's doing the work. Interesting, encouraging, and not a decision.

Your coast number — about $1.49 million for a couple five years from a $2 million target — tells you when the next dollar is free to choose its job. And past that line, the expert move usually isn't more of the account you've already won with. It's the cash bridge, the taxable flexibility, the deliberate spending — the parts of a real plan that a 401(k) statement never shows.

Retirement may last 30 years, but it is not 30 equal years. The grind that keeps you saving may prevent you from enjoying what you were saving for.

That's the honest version of "saving is optional." Nothing about your carefulness gets thrown away. The 401(k) did its job, the discipline keeps its job, and the only thing that changes is the assignment.

You already know your number. Now you know what it frees.

Saving got you to the coast. What you build next is what gets you across the water.

Let's Find Your Coast Number Together

If you'd like a set of eyes on your whole picture — the coast math, the cash bridge, the Roth conversion runway, all of it, coordinated — schedule a free consultation. I work with clients in Honolulu and virtually across the country. Not sure where you stand yet? Start with my free Retirement Readiness Assessment.

— Daniel Masuda Lehrman, CFP®, Founder of Masuda Lehrman Wealth. Mahalo for reading.

This article is for educational purposes only and is not personalized financial, tax, or legal advice.