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 investors' portfolios.

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

Victory Munder Multi-Cap A (MNNAX): 1.21% expense ratio and 0.75% management fee. MNNAX is a Sector - Tech mutual fund, allowing investors to own a stake in a notoriously volatile sector with a much more diversified approach. MNNAX has achieved five-year annual returns of an astounding 15.86%.

American Funds Washington Mutual Investors 529F (CWMFX) is a stand out amongst its peers. CWMFX is a part of the Large Cap Value category, and invests in equities with a market capitalization of $10 billion or more, but whose share prices do not reflect their intrinsic value. With five-year annualized performance of 11.99%, expense ratio of 0.43% and management fee of 0.22%, this diversified fund is an attractive buy with a strong history of performance.

MFS Blended Research Intl Eq R3 (BRXTX Quick QuoteBRXTX - Free Report) : 0.75% expense ratio and 0.35% management fee. BRXTX is a Non US - Equity option, focusing their investments acoss emerging and developed markets, and can often extend across cap levels too. With a five-year annual return of 12.26%, 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.