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Target Date Funds vs DIY — The Honest Comparison

Target date funds are a sensible default. DIY index funds are cheaper. Here's when the extra effort is worth it.

The Speedrun Take

Target date funds are not a bad choice — they're a great default. A Fidelity Freedom Index 2055 fund holds thousands of stocks and bonds globally, rebalances automatically, and adjusts more conservative as you approach retirement. The cost: ~0.12% expense ratio. The DIY alternative: FZROX + FZILX + bond fund for essentially 0.00–0.03%. Both are infinitely better than picking individual stocks or leaving money in cash.

What Is a Target Date Fund

A target date fund (TDF) is a single fund that holds a globally diversified mix of stocks and bonds. You buy one fund and it manages everything inside automatically.

Automatic glide path

Starts aggressive (mostly stocks 30 years out), shifts conservative as your target year approaches

Set it and forget it

Pick your estimated retirement year — 2050, 2055, 2060. One fund, total portfolio.

Built-in rebalancing

The fund rebalances its internal allocation for you. No action required on your part.

The Two Types of Target Date Funds

Not all target date funds are the same. The key distinction is what's inside them.

Index-based TDFs — Choose These

Holds low-cost index funds inside. Examples: Fidelity Freedom INDEX funds (look for "INDEX" in the name), Vanguard Target Retirement funds. Low cost: 0.10–0.15% ER.

Actively Managed TDFs — Avoid These

Holds actively managed funds inside. Examples: Fidelity Freedom (not index), T. Rowe Price. Higher cost: 0.40–0.75% ER. The extra cost rarely pays off.

The rule

Always check if an "index" version is available in your 401k fund menu. Choose index over active every time.

TDF vs DIY Comparison

DIY portfolio (FZROX + FZILX + bond fund) vs a target date index fund — head to head.

FactorTarget Date FundDIY (FZROX + FZILX + bond)
Expense ratio0.10–0.15%0.00–0.03%
Number of funds1 fund2–3 funds
Automatic rebalancingYesNo (manual or not at all)
Automatic glide pathYesNo (you control allocation)
Best in401k (limited fund selection)Roth IRA or taxable (full fund access)
Effort requiredMinimalLow–medium (check 1–2x/year)

When Target Date Funds Win

Your 401k has limited fund selection and a TDF index fund is the only diversified option

You genuinely want zero maintenance — one fund for your entire investing life

You're starting out and don't want to think about asset allocation

You're close to retirement and want automatic de-risking handled for you

When DIY Index Funds Win

You have access to Fidelity ZERO funds (0.00% ER) — the cost savings compound over decades

You want control over your bond allocation (TDFs may hold more bonds than you want in your 40s)

You have multiple accounts and want to manage allocation holistically across all of them

You're in a high-income situation where every basis point of fees matters

The Fee Math Over 30 Years

$100,000 invested for 30 years at 8% annual growth. The compounding fee drag is real.

OptionExpense RatioEnd Balance
TDF (index-based)0.12%~$940,000
DIY (VTI/VXUS)0.015%~$990,000
FZROX (Fidelity ZERO)0.00%~$1,006,000

The gap

The gap between TDF at 0.12% and FZROX at 0.00% is approximately $66,000 on a $100k starting amount over 30 years. On larger portfolios, that number scales proportionally.

Get the 0% Expense Ratio Option

Fidelity has both Fidelity Freedom INDEX target date funds and the FZROX/FZILX ZERO funds — no account minimum, no fees to open.

Open a Fidelity account

The "Good Enough" Principle

At small portfolio sizes under $50,000, the fee difference between a TDF and DIY is less than $500 per year. The math doesn't justify the mental overhead for most people starting out.

The right answer is the one you implement

A TDF you open today beats a DIY portfolio you "get around to" next year. Inaction is the most expensive financial mistake.

Don't let perfect be the enemy of good

If you're in a 401k with limited options and a good TDF index fund is available, that is the answer. Optimize later when the numbers matter more.

How to Find a Good Target Date Fund

Look for "index" in the name and an expense ratio under 0.25%. Here are the ones worth choosing — and the ones to avoid.

FundERVerdict
Vanguard Target Retirement 20XX0.08–0.10%Excellent
Fidelity Freedom INDEX 20XX0.12%Excellent
Schwab Target Date Index0.08%Excellent
Fidelity Freedom 20XX (non-index)0.40–0.75%Avoid — actively managed
T. Rowe Price Target Date funds0.40–0.75%Avoid — actively managed

Rule of thumb: if the expense ratio is above 0.25%, it's an actively managed TDF. Skip it and find the index version.

Related Guides

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Open Fidelity — Access the Best TDFs and Index Funds

Fidelity has both Fidelity Freedom INDEX target date funds and the FZROX/FZILX ZERO funds. No account minimum, no fees to open. Start in 10 minutes.