An annuity is the only financial product that can guarantee you an income for as long as you live, a paycheck you cannot outlive no matter how long that is. That is a powerful promise, and it is exactly why annuities are both beloved by retirees and aggressively sold by agents who collect commissions. The key is telling apart the handful of annuity types that are simple and fair from the many that are complex and expensive. This page focuses on the simplest kind, the SPIA annuity, single premium immediate annuity, and on how immediate annuity rates translate into monthly income.
What Is an Annuity?
An annuity is a contract with an insurance company. You hand over a lump sum, the premium, and in exchange the insurer promises to pay you a stream of income, typically monthly, for a set period or for life. The core appeal is longevity insurance. Unlike a savings account you can outspend or a portfolio you can outlive, a lifetime annuity keeps paying for as long as you draw breath.
Annuities come in two big dimensions. Immediate versus deferred: an immediate annuity starts paying within a year, usually within 30 days, while a deferred annuity is bought now and starts paying years later. Fixed versus variable: a fixed annuity pays a set, predictable amount, while a variable annuity's payments depend on underlying investments and can go down.
The shorthand you will see everywhere looks like this:
| Type | What it pays | Complexity | Typical fees |
|---|---|---|---|
| SPIA (single premium immediate annuity) | Fixed, guaranteed, starts now | Low | Low |
| Deferred income annuity (longevity annuity) | Fixed, guaranteed, starts later | Low | Low |
| Fixed annuity | Fixed return, then income | Low to medium | Medium |
| Variable annuity | Market dependent | High | High |
| Equity-indexed annuity | Index tied with caps and floors | High | High |
For the rest of this page the focus is on SPIAs, the plain, immediate, fixed version, because they are the ones where the numbers are honest and the comparison to other retirement income is meaningful.
SPIA Annuity: How It Works
A SPIA is the simplest annuity there is. You give an insurer $100,000 and they promise to pay you a fixed amount every month for the rest of your life. If you live to 90, they keep paying. If you die at 68, the payments stop, unless you bought a period-certain or refund rider. That mortality risk is precisely what the insurer is pricing, which is why older buyers get higher payouts.
The trade you are making is brutal but clean. You give up control of the principal in exchange for guaranteed income. You cannot withdraw the $100,000 later. You do not get the leftover when you die, without riders. And the payments are fixed, a real weakness in an inflationary world, which is why most retirees pair a SPIA with other assets rather than betting everything on one.
What you can add, for a price:
- Period certain, such as 10-year or 20-year certain. Payments continue to a beneficiary if you die early. It costs a slice of your payout.
- Joint life. Payments continue while your spouse lives.
- Inflation rider. Payments rise annually with inflation, typically measured by CPI. It significantly reduces the starting payout in exchange for future protection.
- Cash refund. If you die early, your beneficiary gets back whatever principal was not paid out.
Each rider is an insurance product inside the annuity, and each one reduces the base payout. The base, life-only version is always the largest monthly number.
Immediate Annuity Rates: What $100,000 Buys
The payout rate is the number that matters. It is the annual income expressed as a percentage of your premium, and it is set at purchase based on your age, your gender, interest rates, and the insurer's assumptions. Because women live longer on average, a woman receives a slightly lower monthly payout than a man of the same age for the identical policy. Rates also move with the broader interest rate environment, so the generosity of immediate annuity rates changes over time.
A worked example makes it concrete. Suppose you are quoted a 6% payout rate on a life-only SPIA. On $100,000 that is $6,000 a year, or $500 a month, for life. At a 7% quote it is $7,000 a year, or about $583 a month. The two numbers are the same product, and the difference is entirely the quote you found by shopping:
| Quote on a life-only SPIA per $100,000 | Annual income | Monthly income |
|---|---|---|
| 6% | $6,000 | $500 |
| 6.5% | $6,500 | $542 |
| 7% | $7,000 | $583 |
That is why shopping matters. Rates vary by hundreds of dollars a year between insurers for the identical product, because each insurer prices its own mortality and expense assumptions. Get at least three quotes from different carriers, and ask each for the same structure, life only or life plus period certain, so the comparison is apples to apples. No single provider is the cheapest for every age and state, and your money is protected up to state limits by the guaranty associations in the state where you buy.
Annuities and the 4% Rule: Where a SPIA Fits
The FIRE community spends a lot of time on the 4% rule and on withdrawal strategies, which are built on a portfolio that can be depleted by a bad sequence of returns. A SPIA is not an investment, it is income insurance, and it plays a specific role in a plan.
- Cover the floor. Use a SPIA to cover your essential expenses, the baseline that must be paid no matter what. That is the number our retirement expenses calculator helps you find.
- Buy it at retirement, not decades earlier. Immediate annuities start paying right away. Deferred annuities tie up cash for years, and the flexibility loss rarely pays for itself in a FIRE timeline.
- Never annuitize everything. Keep two to five years of expenses liquid and the rest invested, so you stay in control and keep pace with inflation.
- Compare it to what it replaces. A SPIA is competing against a bond-heavy withdrawal portfolio, and the right comparison is guaranteed income against a safe withdrawal rate, not against stock returns.
There is research, including work by Wade Pfau and the Bogleheads community, showing that laddering a SPIA into retirement income can reduce the risk of running out of money, because it covers fixed baseline expenses with guaranteed income and lets the portfolio absorb variable spending. The mechanism is sound: you are transferring the risk of living long to an insurer built to price it.
Social Security Is the Best Annuity
Before you buy any annuity, remember that Social Security is an inflation-indexed, lifetime annuity, and it is usually the best one you will ever be offered, because it is adjusted for inflation every year. Delaying Social Security to 70 increases the monthly benefit for life and is, for most people, a better "annuity purchase" than any private product on the market. Our Social Security and FIRE optimization guide covers the claiming math. If you are buying a private annuity before you have maximized your Social Security claiming decision, check that ordering first.
Annuity Costs and the Traps to Avoid
The SPIA is refreshingly cheap. No ongoing fees, just the insurer's built-in spread. The complex annuities are where the costs hide.
- Variable annuities routinely carry annual costs that can total several percent once mortality, administrative, and fund expenses are added, plus surrender charges for cashing out in the early years.
- Equity-indexed annuities hide costs in caps and participation rates that the insurer can reset, often making actual returns far worse than the advertised index-linked gains.
- Surrender periods lock up your money for years, and breaking the contract early triggers steep penalties.
- Commissions. Complex annuities pay agents large commissions, which is why they are so aggressively pitched to seniors. The commission comes out of your returns, one way or another.
The SEC and the CFPB have both flagged annuity sales tactics as a major consumer protection issue. Two rules of thumb keep you out of trouble. If you cannot understand the payout formula in two minutes, you are paying for complexity you do not need. And any agent pushing a variable or indexed annuity over a SPIA or a low-cost index portfolio deserves extra skepticism. The National Association of Insurance Commissioners and state insurance regulators also publish buyer's guides that are worth reading before you sign anything.
Common Annuity Mistakes
- Buying complexity you do not understand. Variable and indexed annuities carry fees and features that most buyers never fully price. Start with the simple SPIA and add nothing you cannot explain to a friend.
- Skipping the quote comparison. Payout rates vary between insurers for the identical product. Three quotes is the minimum.
- Annuitizing everything. Putting the whole portfolio into a fixed annuity leaves no inflation protection and no liquidity. The floor approach, essential expenses only, is the safe structure.
- Ignoring the inflation rider decision. A fixed payment buys less every year. Either buy the rider or pair the annuity with assets that grow.
- Buying before the Social Security decision. Delaying Social Security is usually the better inflation-adjusted annuity, and buying a private one first can be an expensive ordering error.
- Trusting an agent's payout illustration without the contract. The guarantee is in the written contract, not the sales brochure. Read it before you sign.
FAQ
What is a SPIA annuity? A single premium immediate annuity. You pay a lump sum and the insurer pays a fixed monthly income for life, starting within about a year of purchase.
How do immediate annuity rates work? The payout rate is the annual income as a percentage of your premium, set at purchase based on your age, gender, and current interest rates. Higher age means a higher rate, because the insurer expects to pay for fewer years.
What is a good immediate annuity rate? There is no fixed benchmark, because rates move with the interest rate environment and vary by insurer. The right comparison is between quotes for the identical structure, and against what your own portfolio can safely pay.
Are annuities a good investment? A SPIA is not an investment, it is income insurance. It guarantees a floor for life in exchange for giving up control of the principal. Whether that trade is good depends on your age, your expenses, and your other assets.
Can I lose money on an annuity? On a SPIA, no, the payments are contractual, but inflation erodes their purchasing power and you cannot get the principal back. On variable and indexed annuities, yes, the value can fall with the market and fees.
Are annuities taxable? Income from an annuity bought with after-tax money is partly a return of principal and partly taxable growth. The tax treatment depends on the account type and how it is funded, so the details belong to a tax professional.
The Bottom Line
An annuity is a trade: a lump sum for guaranteed lifetime income, and the SPIA is the simple, low-cost version of that trade. Immediate annuity rates are set at purchase and vary by age, gender, and insurer, so shop several carriers and compare identical structures. Use a SPIA to cover the essential-expense floor in a retirement plan, keep several years of expenses liquid, and never buy complexity you cannot explain. Before any private annuity, make the Social Security decision first, because it is the best inflation-adjusted annuity most people will ever own. Our can I FIRE calculator will tell you whether your plan already stands on its own; if it does, a SPIA becomes optional income insurance rather than a necessity.
Related Calculators
Sources
- U.S. Securities and Exchange Commission: What to know about annuities
- FINRA: Annuities
- Consumer Financial Protection Bureau: Annuities and retirement products
This article is for educational purposes only and is not financial advice. Consult a qualified professional before making financial decisions.