Certificates of deposit offer higher yields to savers who are willing to lock their money up for a specific period of time. iStockphoto By the editors of Kiplinger's Personal Finance Updated January 2015 CDs have a lot to offer the safety- and yield-minded saver. Virtually the only catch is that if you need the money before the CD matures, you'll pay a penalty that could eliminate the advantage you thought you were getting from the higher rate. For that reason, CDs are good for people looking for maximum yields, but who will not need their cash unexpectedly.You'll get a higher-than-passbook rate of interest in return for your commitment to leave the money deposited for a specified time, commonly from a minimum of a month or so to a maximum of five years. The longer you commit your money -- and, in some cases, the more money you commit -- the more you earn. The interest rate is usually fixed but can vary based on market conditions, such as the rise or fall of the prime rate. Minimum deposits are often $500 to $1,000, though the best rates may require higher minimums. How to shop for CDs By spending just a half-hour or so shopping for the best rates, you can probably earn an extra one to two percentage points on your next certificate of deposit. With a $25,000 CD, that's an extra $250 to $500 earned in one year and from $1,275 to $2,600 over five years. Advertisement Buy from a bank. Start by calling local banks and thrifts to compare rates. For each CD maturity, ask for the; Annual percentage rate (or APR, which reflects the compounding of interest). Minimum deposit amount. The penalty for early withdrawal. How you'll be notified when the CD matures. You should also make sure deposits are insured by the Federal Deposit Insurance Corp. FDIC insures deposits of up to $100,000 per person, per type of account (such as savings, CD and IRA) per bank. For example, you could have a $100,000 CD in your name, keep $50,000 in a demand deposit in a joint account in your and your spouse's names and be fully insured up to $150,000. (For details, visit the FDIC's Web site.) Next, broaden your search. Going national could reward you with a yield of up to two percentage points more. If a deposit is insured by the FDIC, you're as safe with a CD offered by a bank 2,000 miles away as one around the corner. Bankrate.com tracks the most generous CD yields offered by banks and thrifts around the country. (Search the latest rates or research the bank, thrift or credit union for stability.) Buy from a Broker. A brokerage firm can generally offer you an above-average yield on a federally insured CD. Because issuing banks pay a fee to brokers who parcel out their CDs this way, the customer usually doesn't have to pay a commission. And because brokerage firms that do this sort of packaging usually maintain an active secondary market for their CDs, you can often sell them back before maturity without paying the penalty a bank or s&l would charge for early withdrawal. But the privilege of cashing in your CD early with no penalty may come at a price. Advertisement If interest rates rise between the day you purchase the CD and the day you cash it in early, you won't get back as much as you paid for it. (On the other hand, if rates have fallen, you should get more.) This is because a CD in the secondary market is in many respects a short-term bond, and the usual relationship between bond values and market rates will be at work: When interest rates rise, the value of outstanding bonds falls; when rates fall, bond values rise. Skip the Gimmicks Some banks and s&l's have devised yield-boosting gimmicks to attract new money. The "bump-up" CD and market-indexed CD are popular ones. Bump-ups generally start you at a lower rate but promise to raise it if interest rates rise during the term of your CD. However, they are usually crafted to favor the bank and you'd typically be better off if you lock in at the higher rate. Market-indexed CDs are tied to the performance of the overall stock market and essentially expose you to market risks without delivering all the potential rewards. You'd be better off putting your cash into regular CDs and your long-term savings into a stock-index mutual fund.