Investing in mutual funds for retirement is never too late. And the Zacks Mutual Fund Rank can be an excellent tool for investors looking to invest in the best funds.

How can you tell a good mutual fund from a bad one? It's pretty basic: if the fund is diversified, has low fees, and shows strong performance, it's a keeper. Of course, there's a wide range, but using the Zacks Mutual Fund Rank, we've found three mutual funds that would be great additions to any long-term investors' portfolios.

Let's learn about some of Zacks' highest ranked mutual funds with low fees you may want to consider.

Fidelity Advisor Stock Select Allocation Cap Z (FZAPX Quick QuoteFZAPX - Free Report) has a 0.46% expense ratio and 0.41% management fee. FZAPX is a Large Cap Growth option; these mutual funds purchase stakes in numerous large U.S. companies that are expected to develop and grow at a faster rate than other large-cap stocks. With yearly returns of 12.99% over the last five years, this fund clearly wins.

American Funds Washington Mutual Investors R2 (RWMBX): 1.35% expense ratio and 0.22% management fee. RWMBX is a Large Cap Value mutual fund, which invests in stocks with a market cap of $10 billion of more, but whose share prices do not reflect their intrinsic value. With yearly returns of 10.96% over the last five years, RWMBX is an effectively diversified fund with a long reputation of solidly positive performance.

Third Avenue Value Fund Institutional (TAVFX): 1.14% expense ratio and 0.9% management fee. TAVFX is a Small Cap Value mutual fund, investing in small companies with stock market valuation less than $2 billion. The fund is mainly invested in equities, has a long reputation of salutary performance, and has yearly returns of 14.46% over the last five years.

There you have it. If your financial advisor had you put your money into any of our top-ranked funds, then they've got you covered. If not, you may need to talk.