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.

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 retirement investors' portfolios.

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

Columbia Small Cap Value II Class Z (NSVAX Quick QuoteNSVAX - Free Report) : 1.01% expense ratio and 0.83% management fee. NSVAX is a Small Cap Value mutual fund option, which typically invest in companies with market caps under $2 billion. NSVAX has achieved five-year annual returns of an astounding 8.13%.

AQR Large Cap Multi Style N (QCENX Quick QuoteQCENX - Free Report) : 0.65% expense ratio and 0.25% management fee. QCENX is a Large Cap Blend fund, targeting companies with market caps of over $10 billion. These funds offer investors a stability, and are perfect for people with a "buy and hold" mindset. QCENX, with annual returns of 12.1% over the last five years, is a well-diversified fund with a long track record of success.

Frost Growth Equity Institutional (FICEX Quick QuoteFICEX - Free Report) : 0.64% expense ratio and 0.5% management fee. FICEX is a Large Cap Growth mutual fund, and these funds invest in many large U.S. firms that are projected to grow at a faster rate than their large-cap peers. With a five-year annual return of 14.32%, this fund is a well-diversified fund with a long track record of success.

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.