Maybe it’s time to go long. Or medium. Short is so, so : last summer.

I’m talking about interest-paying investments such as certificates of deposit and government and corporate bonds.

Now that interest rates seem to have leveled off, it might pay to lock up good rates with longer-term investments in case rates fall next year.

The best five-year CDs, for example, pay upward of 5 percent. You can do just as well with a top one-year CD, but when it matures a year from now, you might not have the chance to reinvest that money at a rate as good as you can get today.

Normally, long-term interest-paying investments carry higher yields than ones with shorter terms, compensating investors for tying up their money.

But that hasn’t been the case recently. While the Federal Reserve spent more than two years pushing short-term rates up to stem inflation, long-term rates stayed relatively low, apparently because bond traders didn’t share the Fed’s worries about inflation.

In June, for example, U.S. Treasury bills with six months to maturity paid 5.2 percent, while 10-year Treasuries paid 5.1 percent.

Since many people at that time worried that interest rates would rise, it made more sense to put money into short-term investments so it could be reinvested at a higher rate later.

Now things have changed. The Fed has stopped raising short-term rates, and a drop in wholesale prices in October suggests inflation is less threatening. A Fed official recently described current rates as “about right,” encouraging analysts to think the Fed might cut rates next year.

Of course, you don’t have to bet your whole wad on one extreme or the other – you can get several interest-paying investments with short, medium and long periods to maturity.

That’s called laddering. Bankrate.com, the rate-tracking outfit, has a useful calculator for figuring the best laddering strategy. Go to www.bankrate.com and click the calculators tab. The site is also a good place to shop for CDs.

While we’re talking about interest rates, how has the changing situation affected the appeal of various types of mortgages?

It hasn’t.

The best deals are still in 30-year fixed-rate mortgages. Their rates average about 6.3 percent nationally, though many lenders offer 6 percent or even less. That’s pretty good.

The 15-year fixed loan averages about 6 percent. That’s not enough savings to offset the fact that monthly payments are much higher if the loan has to paid off in 15 years instead of 30. I’d get a 30-year loan and try to pay it off faster.

Adjustable-rate loans haven’t been a good deal for years and still aren’t. They average around 5.8 percent for the first 12 months, not enough of a discount to offset the risk of a higher rate at some future annual adjustment.

And even if short-term rates come down next year, there’s not much chance an ARM will adjust downward. To do so, the index it keys off, such as Treasury bonds with one year to maturity, would have to fall to just more than 3 percent, which is rare.

If you missed buying inflation-indexed U.S. Savings bonds before the new rates were set Nov. 1, don’t feel bad – the new ones are just as good.

The government did not, as some had feared, cut the fixed-rate portion of I bonds’ yields – the part that matters. That stayed at 1.4 percent.

The variable rate, good for the first six months you own the bond, is 3.1 percent. Thus, the new bonds’ combined rate for the first six months you have them will be 4.52 percent. The fixed rate will stay the same for 30 years, while the variable rate will be adjusted every six months to match inflation.

Bonds sold from May 1 through October paid 2.41 percent. If you bought those bonds, don’t worry; they’ll jump to 4.52 percent after you’ve had them for six months. That’s because they carry the same 1.4 percent fixed rate, and at the next adjustment their variable rate will rise to the level set Nov. 1.