There is never a wrong time to invest in mutual funds for retirement. So, if you're still looking for the best mutual funds, the Zacks Mutual Fund Rank can be a great guide.

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.

Here are the funds that have achieved the Zacks Mutual Fund Rank #1 (Strong Buy) and have low fees.

If you are looking to diversify your portfolio, consider

Fidelity Value Fund K

(FVLKX Quick QuoteFVLKX - Free Report) . FVLKX is a Mid Cap Value mutual funds that aims to target medium-sized companies that possess strong value and income opportunities for investors. This fund is a winner, boasting an expense ratio of 0.74%, management fee of 0.72%, and a five-year annualized return track record of 15.48%.

Janus Henderson Global Research T

(JAWWX Quick QuoteJAWWX - Free Report) : 0.86% expense ratio and 0.59% management fee. JAWWX is a Global - Equity mutual fund. These funds invest in large markets like the U.S., Europe, and Japan, and operate with very few geographical limitations. JAWWX, with annual returns of 14.77% over the last five years, is a well-diversified fund with a long track record of success.

Putnam Small Cap Growth Y

(PSYGX Quick QuotePSYGX - Free Report) : 0.96% expense ratio and 0.7% management fee. PSYGX is a Small Cap Growth mutual fund and tends to feature small companies in up-and-coming industries and markets. With a five-year annual return of 12.73%, 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.