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 retirement investors' portfolios.

Let's break down some of the mutual funds with the top Zacks Mutual Fund Rank and the lowest fees.

FMI Common Stock Institutional (FMIUX Quick QuoteFMIUX - Free Report) : 0.88% expense ratio and 0.82% management fee. FMIUX is a Mid Cap Blend mutual fund, and usually features a portfolio with stocks of various styles and sizes, allowing for diversification within a strategy that focuses on mid cap companies. FMIUX has achieved five-year annual returns of an astounding 10.85%.

MFS Mass Investors Growth Stock R2 (MIRGX Quick QuoteMIRGX - Free Report) . Expense ratio: 0.96%. Management fee: 0.33%. MIRGX 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. This fund has managed to produce a robust 13.45% over the last five years.

State Farm Growth Fund (STFGX Quick QuoteSTFGX - Free Report) . Expense ratio: 0.12%. Management fee: 0.1%. Five year annual return: 12%. STFGX 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.

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.