How Annuities Work: A Complete Guide for Retirees

If you've ever sat across from an insurance agent explaining annuities, you've probably left the meeting more confused than when you walked in. That's not an accident. Annuity products are intentionally complex — and the people selling them earn commissions of 5–10% of your principal, which creates a strong incentive to obscure how the math actually works.

This guide strips away the jargon. We'll explain exactly what an annuity is, how each type generates income, what fees eat into your returns, and when an annuity actually makes sense.

What Is an Annuity?

At its core, an annuity is a contract between you and an insurance company. You give them a lump sum of money (or a series of premium payments). In exchange, they promise to pay you back in installments — either for a set number of years, or for the rest of your life.

The insurer makes money by investing your principal at a higher rate than they pay you. The longer they hold your money, the more they earn. That's the basic business model.

Annuities are not bank products. They are not FDIC-insured. They are backed by the claims-paying ability of the issuing insurance company. State guaranty associations provide partial protection (usually $250,000–$500,000) if the insurer fails — but that's not federal insurance.

The Three Main Types of Annuities

There are three primary structures, each with very different risk and return profiles.

| Type | How Returns Are Set | Risk | Typical Annual Return | Best For | |---|---|---|---|---| | Fixed | Insurer guarantees a flat rate for a period (e.g., 5.5% for 7 years) | Lowest | 4.0% – 6.5% | Retirees who want certainty, no market exposure | | Variable | Your principal is invested in subaccounts (similar to mutual funds) | Highest | -10% to +15% (varies) | Investors with longer horizons who can tolerate volatility | | Indexed | Returns tied to a market index (S&P 500) with caps and floors | Medium | 3.0% – 7.5% | Conservative investors wanting some upside |

Within each type, there are two timing variations:

• Immediate annuity — you pay a lump sum and start receiving payments within a year
• Deferred annuity — you pay now (or over time) and start receiving payments later, often at retirement

Use our free Annuity Calculator → to see how the math works for any combination.

Fixed Annuities: The Simplest Option

A fixed annuity works like a CD on steroids. You deposit a lump sum. The insurer credits a guaranteed rate of interest for a defined period (typically 3, 5, 7, or 10 years). At the end, you can either renew, take a lump-sum withdrawal, or annuitize (convert the balance into a stream of payments).

Multi-year guaranteed annuities (MYGAs) are the cleanest fixed product. They lock in a single rate for the full term — for example, 5.75% for 7 years. You know exactly what you're getting.

The trade-off is liquidity. Most fixed annuities have surrender charges for early withdrawal — typically 7–10% in year one, declining to 0% by the end of the surrender period. If you need access to the money before then, you'll pay.

Variable Annuities: The Most Expensive Choice

Variable annuities invest your principal in subaccounts that work like mutual funds. Your account balance and ultimate payout fluctuate with market performance.

The pitch sounds appealing: market upside plus optional guarantees through "living benefit riders" like Guaranteed Minimum Withdrawal Benefits (GMWBs).

The reality: variable annuities are widely criticized for their fee structure. A typical contract layers:

• Mortality and Expense (M&E) fees — ~1.25% per year
• Subaccount management fees — 0.5%–1.5% per year
• Administrative fees — 0.15%–0.30%
• Rider fees (if you add living benefits) — 0.50%–1.50%

Total annual cost: often 3.0%+ per year. By comparison, a low-cost index fund charges 0.04%. Over 20 years, those fees can erase $200,000+ from a $500,000 account.

Indexed Annuities: The Middle Ground

Indexed annuities credit interest based on the performance of a market index (most commonly the S&P 500), but with two key constraints:

1. A cap — the maximum interest credited in any year (e.g., 6%)
2. A floor — typically 0%, meaning you can't lose principal in a down market

Sounds great in theory. In practice, indexed annuities have a participation rate (you only get a percentage of the index gain, often 70–100%) and dividends are excluded. So if the S&P 500 returns 12% in a year with a 6% cap and 80% participation, you'd get the lesser of: 12% × 80% = 9.6%, or the 6% cap. You get 6%.

Indexed annuities are pitched as offering "stock market returns with no risk." That marketing oversimplifies. Long-term, indexed annuities tend to track somewhere between fixed annuity returns and bond returns.

How Payments Are Calculated

Once you decide to annuitize (convert your balance into income), insurers use the standard amortization formula:

PMT = P × (r / (1 − (1 + r)^−n))

Where:

• P = principal
• r = periodic interest rate (annual rate ÷ payments per year)
• n = total number of payment periods

For a $250,000 fixed annuity at 5.5% paid monthly over 20 years:

• r = 0.055 / 12 = 0.004583
• n = 20 × 12 = 240
• PMT = $250,000 × (0.004583 / (1 − (1.004583)^−240)) = ~$1,720/month

Total payout over 20 years: $1,720 × 240 = $412,800. Total interest earned: $162,800.

Want to run your own numbers? Use the calculator →

When an Annuity Actually Makes Sense

Annuities aren't universally bad. They make sense in specific situations:

• You're worried about outliving your savings (longevity risk). A lifetime annuity guarantees income no matter how long you live.
• You've maxed out 401(k)/IRA contributions and want additional tax-deferred growth.
• You have plenty of liquidity elsewhere and don't need access to this money for 7–10 years.
• You don't trust yourself to manage a lump sum and want forced budgeting through monthly checks.

They typically don't make sense if:

• You're under 50 and have a long time horizon (low-cost index funds usually win)
• You'll need the money in less than 7 years (surrender charges)
• You're being pitched a variable annuity by a commissioned salesperson

For more, see our guide on whether annuities are worth it or compare them head-to-head with a 401(k).

Frequently Asked Questions

Are annuities a good investment? Annuities are insurance products, not investments. They make sense as part of a retirement income strategy if you value guaranteed income over growth.

Can I lose money in an annuity? In a fixed or indexed annuity, you generally cannot lose principal due to market drops. In a variable annuity, you absolutely can. In all annuities, surrender charges and fees can erode value.

What happens to my annuity when I die? Depends on the payout option. Life-only stops at death. Period-certain continues for the remaining term. Joint-and-survivor continues to a spouse.

How are annuity withdrawals taxed? Earnings are taxed as ordinary income when withdrawn. See our annuity tax treatment guide for details.

What's a good annuity rate in 2026? Fixed MYGAs from highly-rated insurers are paying 5.0–6.5% for 5- to 10-year terms. See Fixed Annuity Rates 2026 for current data.

This article is for educational purposes only and does not constitute financial advice. Consult a licensed financial advisor before making any retirement planning decisions.