How Certificate of Deposit Accounts Work
A CD is a time deposit account offered by banks, thrifts, and credit unions. When you open a CD, you agree to deposit a fixed sum of money for a defined period — the term — and the financial institution agrees to pay you a specified interest rate in return. The term can be as short as one day or as long as ten years, though most banks and credit unions focus their offerings in the six-month to five-year range.
At the end of the term — the maturity date — the institution returns your original deposit (principal) plus all accrued interest. If you withdraw your money before the maturity date, you will generally pay an early withdrawal penalty, which is typically expressed as a set number of months of interest.
CDs generally offer higher interest rates than standard savings and money market accounts because you are committing your money for a fixed period and giving the institution more predictability in their funding. The longer the term, the higher the rate typically is — unless the yield curve is inverted, a condition where short-term rates exceed long-term rates due to inflation pressure and monetary policy.
Federal Deposit Insurance: FDIC and NCUA
One of the most important features of CDs is federal deposit insurance. CDs held at FDIC-insured banks are covered up to $250,000 per depositor, per institution, per ownership category. The same coverage applies to share CDs (the credit union equivalent) held at NCUA-insured credit unions.
This insurance means your principal is never at risk regardless of what happens to the financial institution, up to the coverage limit. If you want to hold more than $250,000 in CDs safely, you can spread deposits across multiple institutions or use different ownership categories — individual, joint, and certain retirement accounts — each of which carries its own $250,000 coverage limit at the same institution.
Verify Insurance Before Opening: Always confirm that a bank is FDIC-insured or a credit union is NCUA-insured before opening a CD. You can verify bank insurance at FDIC BankFind (fdic.gov) and credit union insurance at NCUA's credit union locator (ncua.gov). Uninsured institutions do exist, and deposits there carry principal risk.
CD Terms, Compound Interest, and APY
The term you choose directly affects your yield. Longer-term CDs typically offer higher rates because you are committing your money for a longer period. However, this relationship can reverse during periods of high inflation when the Federal Reserve raises short-term rates aggressively — creating an inverted yield curve where 1-year CDs pay more than 5-year CDs.
Interest on most CDs is credited monthly and compounds over the life of the term. Compounding means the interest you earn also earns interest in subsequent periods. The more frequently interest is credited, the higher the effective Annual Percentage Yield (APY) relative to the stated rate. When comparing CDs, always compare APY — not just the stated interest rate — since APY accounts for compounding frequency.
Compare APY, Not Just Rate: Two CDs may advertise the same interest rate but have different APYs depending on how often interest compounds. Monthly compounding produces a higher APY than quarterly compounding at the same rate. The APY is the most accurate single number for comparing CD returns across institutions.
Early Withdrawal Penalties
If you need to access your money before the CD matures, the institution will charge an early withdrawal penalty. The penalty is typically measured in months of interest — for example, 90 days of interest on a 1-year CD or 180 days of interest on a 2-year CD. On longer-term CDs (3–5 years), penalties can be 12 months of interest or more.
In extreme cases — particularly on short-term CDs where little interest has accrued — an early withdrawal penalty can eat into your principal. Before opening any CD, confirm the exact penalty in writing and consider whether you might realistically need the funds before maturity. If there is any meaningful chance you will need the money early, a high-yield savings account or a CD with a shorter term may be a better fit.
Callable CDs
A callable CD gives the bank or credit union the right to terminate the CD early — before the stated maturity date — at their discretion. Institutions typically call CDs when market interest rates fall significantly below the CD's rate, allowing them to stop paying the higher yield. When a CD is called, you receive your full principal and all earned interest to date, but the bank does not pay any penalty for ending the CD early.
Callable CDs often advertise higher initial rates to compensate investors for this risk. Before opening a CD that offers a noticeably higher rate than competitors, ask specifically whether the CD is callable. If it is callable, factor the possibility of early termination into your decision.
Always Ask About Callability: A bank will not volunteer that a CD is callable. Ask directly: "Can you terminate this CD before the maturity date?" Get the answer in writing. Callable CDs introduce reinvestment risk — if the CD is called during a low-rate environment, you may not be able to reinvest at a comparable rate.
Tips for Investing in CDs
- Confirm the maturity date in writing — know exactly when your money becomes available without penalty.
- Ask whether the CD is callable — before opening any CD that offers an unusually attractive rate, determine whether the bank can terminate it early.
- Confirm whether the rate is fixed or variable — a fixed rate provides certainty; a variable rate may rise or fall during the term.
- Ask how often interest is credited — more frequent crediting (monthly vs. quarterly) produces a higher APY at the same stated rate.
- Understand the early withdrawal penalty in full — get the exact penalty terms in writing before committing your money.
- Shop and compare CD rates before opening — rates vary significantly between institutions. Use our CD rate comparison tables to find the best available rates across banks and credit unions nationwide.
