What a CD is and how you lock in your money

A certificate of deposit is an agreement between you and a bank or credit union: you give them a sum of money for a fixed period of time, and they pay you a set interest rate on that money. You cannot withdraw the funds before the term ends without paying a penalty. That penalty is usually a certain number of months' worth of interest — so if your CD pays 4.5% annually and the penalty is three months' interest, you lose roughly 1.125% of your deposit if you break the term early.

The bank uses your money during that time. In exchange, they may provide the rate will not change, no matter what happens to market interest rates. If rates drop, you still get what you locked in. If rates rise, you are stuck with the lower rate — that is the trade-off for certainty.

CDs are FDIC-insured at most banks and NCUA-insured at most credit unions, meaning your deposit is protected up to $250,000 per account owner per institution if the bank fails. This makes them one of the safest places to keep money that you know you will not need for a while.

Key Takeaways

  • You deposit a lump sum, agree not to touch it for a set term (usually three months to five years), and receive a fixed interest rate in return.
  • Breaking a CD early costs you a penalty, typically three to six months of interest, so only open one if you can leave the money untouched.
  • The interest rate is locked in when you open the CD and does not change, even if market rates move up or down.
  • Your deposit is insured up to $250,000 by the FDIC or NCUA, making CDs safer than stocks or bonds but less liquid than a savings account.
  • Interest compounds and is paid either monthly, quarterly, or at maturity, depending on the CD's terms.

How the term length affects your rate

Longer terms usually pay higher rates than shorter ones. A three-month CD might pay 4.0%, while a five-year CD from the same bank might pay 4.75%. The bank pays more because they want to keep your money longer and because inflation risk is higher over five years than over three months.

The shortest common term is three months. The longest is typically five years, though some banks offer ten-year CDs. There are also no-penalty CDs, which let you withdraw early without a penalty, but they almost always pay a lower rate to compensate for that flexibility.

When your term ends, the CD matures. At that point, the bank pays you the principal plus all accrued interest. You then have a short window — usually seven to ten days — to decide what to do with the money: withdraw it, open a new CD, or move it elsewhere. If you do nothing, many banks automatically roll the money into a new CD at the current rate, which may be higher or lower than what you had.

When interest is paid and how it compounds

Interest on a CD is usually paid monthly, quarterly, or at maturity. Some CDs let you choose. The difference matters if you are trying to maximize growth: if interest compounds monthly, you earn interest on your interest each month, which grows your balance faster than if interest is paid only at the end.

For example, a $10,000 CD at 4.5% annual interest paid monthly will earn roughly $37.50 in the first month. In the second month, you earn interest not just on the original $10,000 but on $10,037.50, so you earn slightly more. Over five years, that compounding adds up. If interest were paid only at maturity, you would earn $2,250 total. With monthly compounding, you earn roughly $2,315 — an extra $65 just from earning interest on interest.

The exact amount depends on how the bank calculates it. Some use daily compounding, which is slightly better than monthly. Always check the CD's disclosure document to see the compounding frequency and the annual percentage yield (APY), which accounts for compounding and shows you the true return.

Early withdrawal penalties and what they cost

If you need the money before the term ends, you can withdraw it, but you will pay a penalty. The penalty is usually stated as a number of months' interest. A common penalty is three months' interest, meaning if your CD pays 4.5% annually and you withdraw after one month, you lose roughly 1.125% of your deposit.

On a $10,000 CD, that three-month penalty costs you about $112.50. On a $100,000 CD, it costs $1,125. The longer you wait before withdrawing, the less the penalty hurts, because you have already earned more interest. But if you withdraw very early — say, after one week — the penalty can exceed the interest you have earned, and you will get back less than you deposited.

Some banks charge a flat dollar amount instead of a months-of-interest penalty. Always read the fine print before opening a CD. If there is any chance you will need the money within the term, a no-penalty CD or a high-yield savings account is safer, even if the rate is lower.

How CD rates are set and why they change

Banks set CD rates based on what the Federal Reserve does with short-term interest rates. When the Fed raises rates, banks eventually raise CD rates to compete for deposits. When the Fed cuts rates, CD rates fall. This lag can be weeks or months, so the rate you see today may not be the rate offered next month.

Your rate, once locked in, does not change. But if you are shopping for a new CD, you are shopping in a market where rates move constantly. Checking rates across multiple banks and credit unions can make a real difference. A 4.5% CD at one bank and a 4.75% CD at another might seem close, but on $50,000 over five years, that 0.25% difference adds up to roughly $650 more in interest.

Rate environments also matter. When the Fed is raising rates, it often pays to open a shorter-term CD so you can reinvest at a higher rate when it matures. When the Fed is cutting rates, a longer-term CD locks in a higher rate before it falls. Checking financial news or your bank's website will tell you the direction rates are moving.

CDs versus savings accounts and money market accounts

A high-yield savings account pays interest like a CD, but you can withdraw money anytime without penalty. The trade-off is that savings account rates are usually lower than CD rates, and they can change at any time. A CD locks in a higher rate but locks up your money.

A money market account is a hybrid: it pays more than a regular savings account, lets you write checks or make a few withdrawals per month, but does not lock your money away. The rate is not fixed and can drop, but you have more flexibility than a CD offers.

If you have money you will not need for at least six months to a year, a CD usually pays more. If you might need it sooner or want to keep it accessible, a savings account or money market account makes more sense. Some people use both: a CD for money they are certain they will not touch, and a savings account for an emergency fund.

Opening a CD and what happens at maturity

Opening a CD is straightforward. You visit a bank or credit union's website or branch, choose the term and amount, and fund the account. You will need to provide your Social Security number, address, and proof of identity. The process usually takes a few minutes online or a few minutes in person.

Most banks require a minimum deposit, often $500 to $2,500, though some have no minimum. Some offer higher rates for larger deposits — a $100,000 CD might pay 0.25% more than a $10,000 CD.

When the CD matures, the bank will notify you. You then have a grace period — usually seven to ten days — to decide what to do. If you do nothing, the bank will automatically roll the money into a new CD at the current rate. If you want to withdraw the money or move it elsewhere, you can do so without penalty during this window. After the grace period ends, the new CD term begins, and you are locked in again.

Frequently Asked Questions

Can I add money to a CD after I open it?

No. A CD is a fixed contract: you deposit a lump sum at the start, and that amount stays the same until maturity. If you want to add more money, you have to open a separate CD. Some banks let you open multiple CDs at different times or with different terms.

What happens if the bank fails while I have a CD?

Your deposit is protected up to $250,000 by the FDIC (at banks) or NCUA (at credit unions). If the bank fails, the insuring agency will pay you the full amount of your CD plus accrued interest, up to the limit. This protection is one reason CDs are considered very safe.

Is there a tax on CD interest?

Yes. Interest earned on a CD is taxable income in the year it is earned or paid, depending on how the CD compounds. The bank will send you a 1099-INT form at tax time showing how much interest you earned. If you are in a high tax bracket, the after-tax return on a CD may be lower than it looks.

Should I open a CD if interest rates are rising?

It depends on how fast rates are rising and how long the term is. If rates are rising quickly, a shorter-term CD (three or six months) lets you reinvest at a higher rate sooner. A longer-term CD locks in the current rate, which could be a disadvantage if rates keep climbing. Check financial news to see what experts expect.

Can I use a CD as collateral for a loan?

Yes. Some banks will lend you money using your CD as collateral, and you keep earning interest on the CD while you repay the loan. This is sometimes called a CD-secured loan. The interest rate on the loan is usually slightly higher than the CD rate, but it is lower than an unsecured personal loan would be.