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.

Columbia Seligman Technology & Information A (SLMCX): 1.15% expense ratio and 0.81% management fee. SLMCX is a Sector - Tech mutual fund, allowing investors to own a stake in a notoriously volatile sector with a much more diversified approach. With annual returns of 20.75% over the last five years, this fund is a winner.

FullerThaler Behav SmCap Grow A (FTXAX). Expense ratio: 1.32%. Management fee: 0.85%. FTXAX is one of many Small Cap Growth mutual funds; these funds tend to create their portfolios around stocks with market capitalization of less than $2 billion. This fund has managed to produce a robust 11.09% over the last five years.

Dana Large Cap Equity Fund I (DLCIX Quick QuoteDLCIX - Free Report) . Expense ratio: 0.75%. Management fee: 0.65%. Five year annual return: 13.57%. DLCIX 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.

We hope that your investment advisor (if you use one) has you invested in one or all of the top-ranked mutual funds we've reviewed. But if that isn't the case, it might be time to have a conversation or reconsider this vitally important relationship.