Target Date Funds and the Multi-Account Investor
Most of the households who come to Melby Wealth Management with a target date fund in their 401(k) aren't asking what it is. They already know. They're asking a harder question: now that they have a 401(k), a Roth IRA, a taxable brokerage account, and maybe an HSA, is holding the same target date fund in every one of them quietly costing them money? They want a portfolio that works as a single coordinated system, not four accounts each running their own autopilot.
As a CERTIFIED FINANCIAL PLANNER® (CFP®) professional running a fee-only fiduciary firm in Nashville, this is one of the most common transitions I help clients through: the move from a single all-in-one fund that served them well early on to a coordinated multi-account portfolio that fits a more complicated financial life.
This is the advisor-framed companion to the consumer version I wrote on Melby Money, What Is a Target Date Fund? (And Should You Use One?).
The target date fund solved one problem and created another
I want to be fair to the target date fund before I take it apart, because it solved a real problem. Target date funds hold roughly $4.8 trillion in U.S. retirement plans and serve as the default in 86 percent of 401(k) plans for a reason: they deliver cheap diversification, automatic rebalancing, and a behavioral guardrail that keeps people from making the timing mistakes that wreck long-term returns. For someone who would otherwise freeze up and leave the money in cash, getting them into a diversified fund on autopilot is a genuine win.
The problem is what the autopilot does to a long-horizon investor. The glide path holds bonds at every age, including a 35-year-old's. For a household with two or three decades before they touch the money, that bond sleeve is mostly a drag, and on a meaningful balance the gap compounds into real money. A single percentage point of annual return, carried across 30 years of saving, runs into the hundreds of thousands of dollars. (I worked that number in detail in the consumer version.) So for most of the higher-earning households I work with, the real work is twofold: deciding whether the target date fund was ever the right tool for their timeline, and then coordinating the replacement across their accounts.
That coordination is where the multi-account angle comes in.
Where the single-fund approach starts costing multi-account households
Three issues tend to surface once a household has assets across tax-deferred, tax-free, and taxable accounts.
The first is asset location. Different investments are taxed differently, and different accounts shelter them differently. Bonds generate ordinary-income interest, which is best held inside a tax-deferred 401(k) or traditional IRA. High-growth equities are best held in a Roth, where decades of appreciation come out tax-free. A target date fund holds the same blend of stocks and bonds in every account, which means you're holding bonds in your Roth (wasting the tax-free wrapper on a low-growth asset) and holding fully taxable equity dividends in your brokerage account. A coordinated portfolio places each asset where it's taxed most favorably.
The second is glide path fit. The standard glide path is engineered for an average retiree with average resources and an average income replacement target. A higher earner with a pension, meaningful taxable savings, or a spouse's retirement income may want a more aggressive equity allocation held longer than the default glide path provides, because their portfolio isn't the only thing funding retirement. The target date fund can't know that. It de-risks on a schedule built for someone else.
The third is coordinated rebalancing. When your target allocation lives across four accounts, rebalancing means looking at the whole portfolio as one unit and trading in the accounts where it's most tax-efficient to do so. Four separate target date funds rebalance themselves independently, blind to each other, which is not the same thing as rebalancing the household portfolio.
What a coordinated portfolio looks like
The alternative most multi-account households move toward is a simple set of broad index funds placed deliberately by account. A common structure uses a U.S. total market fund such as VTI, an international fund such as VXUS, and a bond fund such as BND, with the bonds concentrated in the tax-deferred accounts, the highest-growth equities in the Roth, and the tax-efficient broad equity holdings in the taxable brokerage account. The household still holds a single coherent allocation. It's just expressed across the accounts in the order that minimizes lifetime tax drag rather than replicated identically in each one.
There's a fee dimension too. Some employer plans offer their target date funds at 60 to 80 basis points while offering the underlying total market index funds in the same menu at 3 to 5 basis points. For a large balance held over decades, choosing the cheaper building blocks inside the 401(k) and coordinating from there can save a meaningful amount without changing the underlying exposure at all.
The behavioral trade-off is real
Here's the honest counterweight, and it's the reason I don't push every client out of a target date fund. The single fund's greatest strength is that it removes decisions. A coordinated multi-account portfolio reintroduces them. Someone has to maintain the asset location discipline, rebalance across accounts, and resist the urge to tinker when one account looks different from another. For a household that won't reliably do that maintenance, the target date fund can still be the better real-world choice, even when the coordinated portfolio looks better on a spreadsheet. The best portfolio is the one that actually gets maintained.
That maintenance is a meaningful part of what an advisor does. It's also something a disciplined do-it-yourself investor can handle with an annual rebalancing routine and a written plan.
When professional coordination adds value
The households that get the most out of working with a fee-only fiduciary on this question are the ones where the target date fund decision sits alongside several other interacting decisions: asset location across multiple accounts, Roth conversion planning, equity compensation, HSA investment, and a glide path that should reflect the household's full set of resources rather than a generic schedule. We model the allocation as one system, place each holding where it belongs, and build a rebalancing discipline that keeps the whole thing on track.
For the consumer-facing version of this post, including how target date funds work under the hood and whether to use one at all, head over to Melby Money.
Discuss your portfolio strategy
Most of the people who schedule a conversation with us at Melby Wealth Management have never worked with a financial advisor before. That's exactly who we work with. If you've outgrown the single target date fund and want a portfolio that's coordinated across all of your accounts, I'd be glad to walk through it with you. Schedule a meeting.
About The Author
Shaun Melby, CFP® provides fee-only financial planning and investment management services in Nashville, TN through his company Melby Wealth Management.
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