Want a risk-free 5% return? How to buy a 3-month Treasury

The latest spike in bond yields was enough to spook the stock market into a selloff Tuesday, but there’s a silver lining for fixed-income investors: Short-term Treasurys are now touting a risk-free return of 5%.

The latest action follows comments from Federal Reserve Chair Jerome Powell, who said on Tuesday that interest rates are “likely to be higher” than previously expected. “If the totality of the data were to indicate that faster tightening is warranted, we would be prepared to increase the pace of rate hikes,” he said.

The yield on the 3-month Treasury touched a high of 5.015% on Tuesday, the highest level since 2007. (Note: that yield is an annualized yield, not what you would get in just three months.)

Rates on the 1-year and 2-year Treasury note – the latter of which is most sensitive to the Fed’s policy – also popped over 5% on Wednesday morning, reaching levels last seen in 2006 and 2007, respectively. Bond yields move inversely to prices.

Short-term Treasurys are a great way to put idle cash to work, and you can also “ladder” them to get a little interest on your money over a certain term. This means you build a portfolio of issues with different maturities and reinvest the proceeds as they mature.

Investors can get in on the action in a couple of ways.

First, they can purchase Treasurys directly from the U.S. government via TreasuryDirect.gov. They will have to set up an account on the site and link their bank to it. For short-term investors, 4-week, 8-week, 13-week and 26-week T-bills are auctioned every week. Two-year notes are auctioned monthly, and 10-year Treasurys are auctioned every quarter.

If you hold the Treasury to maturity, you aren’t subject to market risk. The bonds generally pay interest twice a year, but for T-bills, the interest you get is the difference between what you paid and the face value you receive at maturity.

Another way for investors to buy Treasurys is through a brokerage firm. This makes recordkeeping easier for investors, especially if they already have an individual retirement account at a given firm.

The issue is that you may be subject to fees and minimum purchase requirements if you buy Treasurys through a brokerage account. Consider that you can buy Treasurys directly from the government with a minimum purchase amount of $100, but a brokerage firm can charge you for broker-assisted trades. Others require that you buy at least $1,000 in Treasurys.

Though Treasurys are considered risk free because their payments are backed by the full faith and credit of the United States government, investors should be aware that the real rate of return they’re earning could be eaten away if inflation rises at a pace greater than the yield. A further risk is they may also miss out on investment opportunities in other assets like stocks.

These bonds may be a great way to get some interest on otherwise idle cash, but they shouldn’t make up the entirety of your portfolio.

–CNBC’s Michelle Fox and Gina Francolla contributed to this story.