It is never too late to invest in mutual funds for retirement. As such, if you plan to invest in some of the best funds, the Zacks Mutual Fund Rank can provide you with valuable guidance.

The best way to shortlist great mutual funds is to ensure solid performance, diversification, and low fees. Some are better than others, but utilizing the Zacks Mutual Fund Rank, we have identified three mutual funds that could be solid additions to one's retirement portfolio.

Let's take a look at some of our top-ranked mutual funds with the lowest fees.

Calvert Equity Portfolio I (CEYIX Quick QuoteCEYIX - Free Report) has a 0.65% expense ratio and 0.55% management fee. CEYIX 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 14.09% over the last five years, this fund clearly wins.

Buffalo Small Cap Fund (BUFSX Quick QuoteBUFSX - Free Report) : 1.01% expense ratio and 0.85% management fee. BUFSX is a Small Cap Growth mutual fund and tends to feature small companies in up-and-coming industries and markets. BUFSX, with annual returns of 12.22% over the last five years, is a well-diversified fund with a long track record of success.

Fidelity Advisor Technology I (FATIX Quick QuoteFATIX - Free Report) . Expense ratio: 0.71%. Management fee: 0.52%. Five year annual return: 14.04%. FATIX is a Sector - Tech mutual fund, allowing investors to own a stake in a notoriously volatile sector with a much more diversified approach.

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.