What Is a Certificate of Deposit (CD)?

A certificate of deposit, or CD, is a savings product where you deposit a fixed sum of money with a bank for a fixed term — typically a few months to several years — in exchange for a fixed interest rate that’s usually higher than a regular savings account pays. The trade-off is liquidity: withdraw the money before the term ends and you typically forfeit some or all of the interest as an early-withdrawal penalty. A CD is, in effect, a loan you make to the bank with a defined start date, end date, and payout.

How a CD works

You choose a term — common lengths run from three months to five years — and deposit a lump sum. The bank pays a fixed rate for that entire term, locked in at the moment you open the CD regardless of what happens to interest rates afterward. At maturity, you get your principal back plus the accumulated interest, and can either withdraw the funds or roll them into a new CD.

Unlike a savings account, you generally can’t add money to a CD after opening it, and you can’t withdraw part of it without penalty before maturity. That rigidity is the whole point: banks can offer a better rate because they know the money is committed for a known period, which is more useful to them for their own lending and planning than money that could disappear from a savings account at any moment.

Fixed rate, fixed term — and the trade-off that implies

Because the rate is locked at opening, a CD is a bet on the direction of interest rates relative to when you buy it. Lock in a rate right before rates fall broadly, and your CD looks great in hindsight — you’re earning more than newly opened accounts. Lock one in right before rates rise, and you’re stuck earning less than what’s newly available, with an early-withdrawal penalty standing between you and moving the money somewhere better.

This is the same fundamental trade-off that shows up in bonds: fixed-income instruments generally trade a known, locked-in return for the flexibility to adapt to changing rates. A bond ladder — staggering maturities so only a portion of your money is locked at any given rate at once — is a common technique to manage that trade-off, and the same laddering approach applies directly to CDs: open several CDs with staggered maturity dates instead of one large CD, so you’re never fully locked into a single rate environment and always have something maturing soon enough to reinvest at whatever the current rate is.

CDs vs savings accounts vs bonds

	Savings account	CD	Bond
Rate	Variable, can change anytime	Fixed for the term	Fixed (for a standard fixed-rate bond)
Access to funds	Anytime	Locked until maturity, penalty for early withdrawal	Can typically be sold before maturity on the secondary market
Typical issuer	Bank	Bank	Government or corporation
Deposit insurance	Yes, up to insurance limits	Yes, up to insurance limits	No — bonds carry issuer credit risk
Minimum commitment	None	Usually a minimum deposit and a fixed term	Varies by bond, often tradable in smaller increments

The deposit-insurance point is a meaningful practical difference from bonds: a CD from an insured bank carries essentially no credit risk up to the insurance limit, since the insurance covers the depositor if the bank fails. A bond’s safety instead depends entirely on the creditworthiness of whoever issued it.

Early withdrawal penalties

Nearly all CDs charge a penalty for withdrawing before maturity, commonly structured as forfeiting some number of months of interest — the exact terms vary by bank and term length, and are typically disclosed at the time you open the account. This penalty is the mechanism that makes the “fixed rate for a fixed term” promise possible; without it, a CD would just be a savings account with extra steps. Some banks offer “no-penalty” CDs with a slightly lower rate in exchange for the ability to withdraw early — a middle ground between the two.

When a CD makes sense

A CD suits money you know you won’t need before a specific date and want to earn a defined return on without market risk — a house down payment fund with a known timeline, or a portion of an emergency fund earning more than a bare savings account while still counting toward compound interest rather than sitting idle. It’s not designed to compete with the return potential of equities or an ETF over a long horizon — for money with a decade-plus timeline, the tighter, more predictable returns of a CD usually make less sense than assets with more room to grow, even accounting for their volatility.

The takeaway

A CD trades liquidity for a fixed, locked-in interest rate over a fixed term — a straightforward way to earn more than a savings account on money you’re confident you won’t need before maturity. The core risk isn’t losing principal, since CDs are typically insured; it’s opportunity cost, either from an early-withdrawal penalty if you need the money sooner than planned, or from locking in a rate that rates later rise past. Laddering CDs across staggered maturities is the standard way to hedge that trade-off.