IUL vs 401(k) Comparison Calculator
Compare Indexed Universal Life insurance against a traditional 401(k) for retirement saving. See projected net returns after fees, caps, taxes, and the IUL's 0% floor.
Year-by-Year Projection
How Indexed Universal Life (IUL) Works
Indexed Universal Life is a permanent life insurance policy where the cash value grows based on a stock market index (typically S&P 500), but with a cap on annual gains and a floor of 0% — meaning you never lose money in a down year. The cash value grows tax-deferred and can be accessed via tax-free policy loans in retirement. The insurance company subtracts cost of insurance (COI), administrative fees, and expense charges from your premiums and cash value annually. Total fees typically run 1.5% to 3.5% per year, much higher than index funds (source: NAIC Indexed Universal Life Buyer's Guide).
How a 401(k) Works
A traditional 401(k) is an employer-sponsored retirement plan where contributions are pre-tax (reducing current taxable income), grow tax-deferred, and are taxed as ordinary income on withdrawal in retirement. 2026 contribution limits: $24,000 for under-50, $31,000 with catch-up. Most 401(k) plans offer index funds with expense ratios of 0.05% to 0.50%. Many employers match contributions — typically 50% match up to 6% of salary — which is essentially a 50% guaranteed return that no IUL can match. Withdrawals before age 59½ generally incur a 10% penalty (source: irs.gov, Publication 575).
The Hidden Cost of IUL Caps and Fees
IUL marketing emphasizes the 0% floor (you can't lose money), but ignores three critical drags on returns. First, the cap: if the S&P 500 returns 25% in a great year, your IUL credits only the cap (typically 9-11%), giving up 14-16% of gain. Over 30 years, this caps-vs-uncapped difference compounds dramatically. Second, dividends are excluded — the S&P 500's historical 10% return includes ~2% dividends, so you're actually compared against a 8% price-only index. Third, annual fees of 2-3% directly reduce your returns. Real-world IUL net returns over 20-30 years typically deliver 4-6% annualized, well below the S&P 500's historical 10% (source: Society of Actuaries 2024 IUL study).
When IUL Might Make Sense
IUL is best suited for high-income earners (>$300K/year) who already max out 401(k), Roth IRA, and HSA, want permanent life insurance, and need additional tax-advantaged growth. The death benefit and tax-free loan access add real value beyond pure investment return. For 95% of Americans, contributing the matched portion of a 401(k), then maxing a Roth IRA, then maxing the rest of the 401(k), then opening a taxable brokerage account in low-cost index funds delivers higher net wealth than an IUL. The CFP Board, Consumer Federation of America, and most independent fiduciary advisors recommend skipping IUL for retirement saving (source: CFA, "Indexed Universal Life Insurance: Consumer Concerns").
IUL vs 401k Comparison — What the SEC and NAIC Say About Illustration Math
If a salesperson hands you an IUL illustration projecting 7–8% annual returns, treat the page like a pitch deck, not a financial plan. Per the SEC Investor Alert on equity-indexed products and the NAIC Life Insurance Center for Insurance Policy & Research, IUL illustrations may use the "Index Account" historical lookback under AG-49, which is the most generous regulatory cap — not a guarantee. The actual cap can be lowered by the insurer at any policy anniversary, the floor of 0% locks you out of upswings after market drops, and the fees compound silently against cash value for 10–20+ years. Run this calculator with three scenarios for honesty: (1) the agent's illustrated 7% return, (2) a 5% mid-case under realistic cap adjustments, and (3) a 4% low-case with 3% annual fees. The gap between scenarios 1 and 3 over 25 years is typically 50–70% of total accumulated wealth — the reason most fiduciary CFPs steer clients to 401(k) + Roth IRA + HSA first.
Last updated 2026-06-14. Sources: SEC Investor Alert, NAIC CIPR — Life Insurance, Consumer Federation of America.
Frequently Asked Questions
Is an IUL better than a 401(k)?
For most people, no. A 401(k) with employer match almost always beats IUL because the match is essentially free money (often a 50% guaranteed return), and 401(k) fees (0.05-0.50%) are far below IUL fees (2-3.5%). IUL may make sense only after maxing 401(k), Roth IRA, and HSA.
What is the IUL cap rate?
The cap is the maximum annual gain credited to your cash value, regardless of how much the index actually rose. Typical 2026 caps are 8% to 11%. If the S&P 500 returns 25%, your IUL credits only the cap. Caps can be lowered by the insurance company at any time.
What is the IUL 0% floor?
The floor protects you from market losses — if the index falls, your cash value doesn't lose value to market performance (though fees still come out). However, you also miss the recovery: if the index drops 30% and recovers 35%, you get 0% then capped 9% — net 9% over two years, while a real index investor recovers fully.
Are IUL withdrawals tax-free?
Withdrawals up to your basis (premiums paid) are tax-free. Beyond basis, you typically use policy loans, which are technically not taxable income — but if the policy lapses, the loan amount becomes taxable retroactively. This 'lapse risk' has caused major tax bills for IUL holders.
What's the typical IUL fee structure?
IUL fees include cost of insurance (rises with age), administrative fees, mortality and expense (M&E), and surrender charges in early years. Total drag is typically 1.5% to 3.5% per year, with surrender charges of 7-15% if you cancel in the first 10-15 years.
Should I cancel my IUL and put the cash in a 401(k)?
This depends on your specific situation — surrender charges, tax basis, alternative coverage needs. Consult a fee-only fiduciary financial planner (NAPFA, XY Planning Network). Many IUL holders end up surrendering policies at a loss after realizing the math.
What about IUL for tax-free retirement income?
The 'tax-free retirement' marketing pitch is misleading. Roth IRA withdrawals are also tax-free in retirement, with much lower fees and no insurance overhead. For high earners hitting Roth IRA income limits, mega-backdoor Roth or HSA work better than IUL for tax-free growth.
IUL vs 401k comparison — how do I read an IUL illustration honestly?
Run three scenarios: agent's illustrated rate (often 7–8%), a 5% mid-case with realistic cap adjustments, and a 4% low-case with 3% annual fees. The mid- and low-case typically cut accumulated wealth by 50–70% over 25 years vs the illustrated number. Per SEC and NAIC, illustrations use the most generous historical lookback under AG-49 — that is a marketing tool, not a guarantee.
Can the insurance company change my IUL cap and participation rate?
Yes. The cap rate and participation rate are not contractually fixed — they reset annually at the insurer's discretion. A cap that started at 11% in year 1 can drop to 8% in year 5 with no notice. Always ask the agent for the policy's minimum guaranteed cap (often as low as 3%) and base your decision on the worst-case math, not the current rate.