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

American Funds AMCAP F2 (AMCFX Quick QuoteAMCFX - Free Report) has a 0.44% expense ratio and 0.29% management fee. AMCFX 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 12.72% over the last five years, this fund clearly wins.

North Square Tactical Growth I (ETFOX). Expense ratio: 1.3%. Management fee: 1.08%. ETFOX is classified as an Allocation Balanced fund, which seeks to invest in a balance of asset types, like stocks, bonds, and cash, and including precious metals or commodities is not unusual. This fund has managed to produce a robust 10.12% over the last five years.

Voya Mid Cap Opportunities Portfolio Adviser (IAMOX): 1.22% expense ratio and 0.79% management fee. IAMOX is a Mid Cap Growth mutual fund. These mutual funds choose companies with a stock market valuation between $2 billion and $10 billion. With a five-year annual return of 10.94%, 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.