DESK / TARGET DATE REPLACEMENT
2026 edition
PORTFOLIO ARCHETYPE
DIY target date replacement with ETFs
Target date funds bundle a three-fund-style portfolio with an automatic age-based glide path. Replacing them with individual ETFs saves roughly 10 basis points per year on expense and gives full control over the glide path. The trade-off: you do the rebalancing yourself.
QUICK VERDICT
read this if nothing elsePick the ETF if
DIY ETF replacement (VTI + VXUS + BND with manual annual rebalancing) if your target date fund charges 0.10 percent or more, you have the discipline to rebalance annually without abandoning the plan in a downturn, and your account allows ETFs.
Pick the index fund if
Stay in the target date fund (VTTSX, VFFVX, FFFGX, etc.) if you want truly hands-off investing, your fund expense is 0.10 percent or below, your account is a 401(k) where ETFs are not available anyway, or you suspect you would not actually rebalance the DIY portfolio consistently.
Target date funds (TDFs) are the dominant default option in modern 401(k) plans. Vanguard Target Retirement 2055 (VTTSX) charges 0.08 percent and holds VTI, VXUS, BND, and BNDX in age-appropriate weights. Fidelity Freedom Index 2055 (FQIFX) charges 0.12 percent. The expense gap versus a DIY three-fund implementation (~0.04 percent) is roughly 4 to 8 basis points per year. Per the Bogleheads target date fund wiki, the bundled product is competitive on cost but not the cheapest option.
The empirical evidence consistently shows that retail investors hold target date funds longer and through more market downturns than self-directed portfolios. The bundled glide-path discipline produces better realised returns for many investors even when the headline expense is slightly higher. The DIY approach saves money only if you actually maintain the discipline.
SECTION 02 / WHAT A TARGET DATE FUND ACTUALLY HOLDS
Underneath the wrapper: VTI, VXUS, BND, BNDX
Vanguard Target Retirement 2055 (VTTSX) holds approximately 54 percent VTI (US total market), 36 percent VXUS (international total market ex US), 7 percent BND (US total bond), and 3 percent BNDX (international total bond hedged). The exact weights drift with the glide-path schedule. Per the VTTSX product page, the underlying holdings update annually as the target retirement year approaches.
Fidelity Freedom Index 2055 (FQIFX) holds Fidelity index mutual fund equivalents (FSKAX, FTIHX, FXNAX) in similar weights. Schwab Target Index 2055 (SWYHX) holds Schwab proprietary mutual fund equivalents (SWTSX, SWISX, SWAGX). All three target roughly the same end allocation; the meaningful differences are expense ratio and international ratio.
The glide path: equity weight starts at roughly 90 percent for funds 30+ years from target and gradually decreases to roughly 50 percent at target year and 30 percent seven years past target. The Vanguard glide path bottoms out at 30 percent equity (the "Target Retirement Income Fund" composition); Fidelity Freedom Index bottoms at 22 percent equity. Different glide paths reflect different views on retirement risk tolerance.
SECTION 03 / THE DIY EQUIVALENT
VTI + VXUS + BND in the right weights
For a 30-year-old replacing VTTSX (Vanguard Target Retirement 2060): hold roughly 56 percent VTI + 36 percent VXUS + 8 percent BND. Blended expense ratio approximately 0.04 percent. Saves 4 basis points per year versus VTTSX at 0.08 percent. On a $200,000 balance, the saving is $80 per year.
For a 50-year-old replacing VFIFX (Vanguard Target Retirement 2040): hold roughly 50 percent VTI + 33 percent VXUS + 13 percent BND + 4 percent BNDX. Saves the same 4 basis points per year.
The glide-path adjustment: Update the bond weight roughly every 5 years as you approach retirement. Add 5 percentage points to the bond allocation each five years from age 50 onwards. By retirement, the equity weight should match the target-date-fund equity weight at the same point in the glide (typically 50 to 60 percent equity at retirement age).
Most DIY-replacement Bogleheads use a simple "120 minus age" rule for equity weight, which lands close to the Vanguard target-date glide path within a few percentage points. See the Boglehead portfolio page for the underlying three-fund construction logic.
SECTION 04 / THE BEHAVIOURAL TRADE-OFF
What the DIY approach actually costs
The headline saving (4 to 10 basis points per year of expense) is real but small in absolute terms. On a $500,000 portfolio that is $200 to $500 per year. Over 30 years with compounding it grows but not dramatically. The expense saving is real; it is not the dominant variable in the decision.
What is more dominant: behavioural discipline. Industry surveys (Vanguard's "How America Saves" annual report, Fidelity's quarterly retirement report) consistently find that target date fund holders maintain higher equity allocations through downturns than self-directed-portfolio holders. The bundled product is essentially a commitment device: you cannot panic-sell just the equity portion of a target date fund in a crash, you can only sell the whole bundle. This produces better realised returns over multi-decade horizons even when the headline expense is slightly higher.
The second hidden cost: rebalancing burden. A DIY three-fund needs annual rebalancing to maintain target weights. If equity has run up 30 percent and bonds are flat, your allocation has drifted toward equity-heavy. Rebalancing means selling appreciated equity (potentially realising taxable gains in a taxable account) and buying bonds. Most DIY investors underestimate this discipline burden.
The third hidden cost: glide-path drift. The DIY approach requires you to manually update the bond weight every 5 years or so as you age. Most DIY investors set the initial allocation and never revisit it. By retirement, this can leave the portfolio meaningfully more aggressive than the equivalent target date fund would have become naturally.
SECTION 05 / WHEN DIY MAKES SENSE
Three scenarios where the swap is worth it
1. Your TDF charges 0.20 percent or more. Some 401(k) plans use high-expense target date funds (American Funds, JPMorgan, T. Rowe Price actively managed) that run 0.40 to 0.80 percent. The DIY saving against these is 30 to 70 basis points per year, meaningful even at modest balances. Use the index target-date funds when offered; switch to DIY if only high-expense options are available and individual index funds are also on the menu.
2. You want a non-standard international or bond allocation. The standard target date fund holds market-cap-weighted international (~40 percent of equity) and starts adding bonds early (~7 percent at age 30). If you want zero international (the Bogle-purist view), or 100 percent equity until age 45 (more aggressive than standard glide), the DIY approach gives you control. The TDF does not.
3. You are tax-loss harvesting in a taxable account. Target date funds in a taxable account are tax-inefficient because they hold both equity and bonds in one wrapper, producing both qualified equity dividends and ordinary-income bond interest in the same fund. The DIY approach lets you place equity ETFs in taxable and bond ETFs in your IRA, optimising the asset placement per the Bogleheads tax-efficient placement framework. See the taxable brokerage page for the placement logic.
DESK Q&A
Frequently asked
Q01Are target date funds bad in a taxable account?
More tax-inefficient than ideal, yes. The bundled fund holds both equity (qualified dividends, low cap-gains distributions) and bonds (ordinary-income interest, occasional cap-gains distributions) in one wrapper. The blended distribution treatment is worse than holding equity-only ETFs in taxable and bond-only funds in an IRA. For a target date fund inside a 401(k), Roth IRA, or Traditional IRA, the wrapper-driven inefficiency does not matter because the account itself shelters distributions.
Q02Should I use the standard 'target year matches retirement year' rule?
Generally yes if you are reasonable risk tolerant. Some investors deliberately pick a target date 10 years past their actual retirement (e.g. age 65 retirement plus VTTSX 2060) to maintain a more aggressive equity weight at retirement. This is sometimes called 'target date plus' investing. The argument: average post-retirement life expectancy is 20+ years, so the portfolio still has time to recover from sequence-of-returns risk if equity weight stays higher.
Q03What is the difference between Vanguard's Target Retirement and Vanguard's Target Index?
Vanguard offers two separate target date fund lineups. Target Retirement (VTTSX, VFFVX, etc.) uses Vanguard mutual fund building blocks (VTSAX, VTIAX, VBTLX) at 0.08 percent total expense. Target Index (also Vanguard but a separate institutional series) uses underlying institutional share classes at slightly lower expense, typically only available inside Vanguard 401(k) plan administration. Both follow the same glide path.
Q04Can I hold a target date fund in my Roth IRA?
Yes, and it is a perfectly fine choice. Inside a Roth IRA the target date fund's tax-inefficiency in taxable accounts is irrelevant because the Roth shelters all distributions. Many Roth IRA holders use a single target date fund (VTTSX or FQIFX) rather than three individual ETFs for set-and-forget simplicity. Expense at 0.08 to 0.12 percent is competitive with the DIY approach.
Q05How often should I rebalance a DIY target date replacement?
Annually is enough for most investors. Quarterly is slightly more precise but adds transaction friction. The most common Boglehead practice: rebalance once per year on your birthday or year-end, plus opportunistic rebalancing when an allocation drifts more than 5 percentage points from target. Rebalance using new contributions when possible (buy more of the under-weighted asset rather than selling the over-weighted) to minimise capital-gains realisation in taxable accounts.
Q06Should I worry about the glide path slowing as I get older?
Yes, this is the single biggest reason most DIY-replacement investors should set a calendar reminder to update their bond allocation every five years. The standard target date fund automatically shifts approximately 5 to 7 percentage points from equity to bonds every five years from about age 45 onwards. Forgetting this update can leave the DIY portfolio meaningfully more aggressive at retirement than intended.
DISCLOSURES / READ BEFORE ACTING
What this page is, and is not
Investment disclaimer
This site provides education and reference. It is not investment advice and is not a substitute for advice from a licensed financial advisor. For licensed advice, search NAPFA or XY Planning Network for fee-only fiduciary CFPs near you.
ETFvsIndexFund.com is independent and not affiliated with Vanguard, Fidelity, Schwab, BlackRock, iShares, Invesco, SPDR, the SEC, FINRA, the IRS, the Investment Company Institute, or Morningstar. Expense ratios, fund minimums, and tax-rate figures cited reflect publicly filed prospectuses and IRS publications and may change. Past performance does not predict future returns.