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.

Nuveen Global Equity Income A (NQGAX): 1.11% expense ratio and 0.71% management fee. NQGAX 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 13.33% over the last five years, this fund is a winner.

Goldman Sachs SmCap Val Insights R6 (GTTUX Quick QuoteGTTUX - Free Report) : 0.83% expense ratio and 0.8% management fee. GTTUX is a Small Cap Value fund, and these funds are known for investing in companies with market caps under $2 billion. With yearly returns of 11.05% over the last five years, GTTUX is an effectively diversified fund with a long reputation of solidly positive performance.

Franklin US Large Cap Equity I (LMTIX): 0.8% expense ratio and 0.7% management fee. LMTIX is part of the Large Cap Blend section, and these mutual funds most often invest in firms with a market capitalization of $10 billion or more. By investing in bigger companies, these funds offer more stability, and are often well-suited for investors with a "buy and hold" mindset. With a five-year annual return of 14.46%, 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.