Have you noticed a few carefully worded letters in those quarterly mailings you've been getting from that mutual fund you invested in when you opened your IRA? Fearful of massive money migration triggered by the rash of industry scandals, mutual fund CEOs are offering some comforting words.

Their advice?: "Please stay put."

That's all well and good, but you might want to do your own due diligence before relaxing. Here are five specific things to look for:

  • Change in management. We spend a lot of words in our How-To Guide talking about how important the fund manager is, so make sure the manager you've chosen is still there. A change is inevitable at some point, of course, and it shouldn't necessarily be a signal to sell. You need to be aware, however, of who is handling your money.

  • Change in fees. This is another key element to watch. Mutual funds are not required to keep fees at the level at which you originally signed up. Your job as a fund shareholder is to make sure that your returns don't suffer from "fee creep." Don't underestimate how much a few percentage points can rob you. Robert Brokamp looks at the difference between paying 0.5% and 1.5% in The Fund Fees You Don't See and answers the $23,211 question: Do fees matter?

  • Change in style. If a fund renowned for buying slow-growth, high-dividend blue chips starts buying the latest wireless optical serving router start-up that just hit the market, sit up and take notice. Keep an eye on your fund's holdings to make sure that they conform to what you think you bought -- and to the label that the fund managers assigned it.

  • A change in turnover. Watch closely the turnover rate of any fund you own. If you want to or have to own mutual funds, look for funds with lower-than-average turnover rates, preferably no higher than 50% and hopefully much lower. For comparison, index fund turnover can be around 5% or lower.

  • Change in performance. This is a tricky one. Occasional, or even somewhat frequent, underperformance is not unusual or unexpected for a good fund. Don't bail on your funds just because they have a bad quarter, year, or even two years. Do track performance, though. If you start seeing poor five-year returns, then it may be time to start looking elsewhere.

When you see a fund make significant changes in any of these areas, it's time to reassess your holding. That doesn't mean that you sell automatically -- some changes are for the better, or at least aren't bad enough to suffer the ill effects of selling. Selling can trigger some costly events. (Here's more on tax rules for selling mutual funds.)

Make a pact with yourself to at the very least keep tabs on these five areas for the funds that you own. Make it as automatic as changing the oil in your car or putting a fresh box of baking soda in your fridge. When the red light on the dash goes on, or the stench of rotten broccoli overwhelms you, it may be too late. And so it goes for mutual fund investing.