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.

AQR Global Equity Fund N

(AQGNX): 1.05% expense ratio and 0.6% management fee. AQGNX 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. With annual returns of 12.41% over the last five years, this fund is a winner.

Fidelity Advisor Growth Opportunit

(FAOFX): 0.01% expense ratio and 0% management fee. FAOFX is a part of the Large Cap Growth mutual fund category, which invest in many large U.S. companies that are expected to grow much faster compared to other large-cap stocks. With yearly returns of 19.28% over the last five years, FAOFX is an effectively diversified fund with a long reputation of solidly positive performance.

Goldman Sachs Tax Adviser Global Equity I

(TIGGX): 0.19% expense ratio and 0.15% management fee. TIGGX is a Non US - Equity option, focusing their investments acoss emerging and developed markets, and can often extend across cap levels too. The fund is mainly invested in equities, has a long reputation of salutary performance, and has yearly returns of 11.92% over the last five years.

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.

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