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.

The best way to shortlist great mutual funds is to ensure solid performance, diversification, and low fees. Some are better than others, but utilizing the Zacks Mutual Fund Rank, we have identified three mutual funds that could be solid additions to one's retirement portfolio.

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 Balanced Fund

(FBALX Quick QuoteFBALX - Free Report) . FBALX is a part of the Allocation Balanced fund category; these funds like to invest in a variety of asset types, finding a balance between stocks, bonds, cash, and sometimes even precious metals and commodities; they are mostly categorized by their respective asset allocation. This fund is a winner, boasting an expense ratio of 0.49%, management fee of 0.38%, and a five-year annualized return track record of 12.07%.

Guinness Atkinson Global Innovators Fund

(IWIRX Quick QuoteIWIRX - Free Report) : 1.24% expense ratio and 0.75% management fee. IWIRX 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 yearly returns of 16.93% over the last five years, IWIRX is an effectively diversified fund with a long reputation of solidly positive performance.

AQR Small Cap Multi-Style R6

(QSERX Quick QuoteQSERX - Free Report) : 0.5% expense ratio and 0.45% management fee. QSERX is a Small Cap Blend mutual fund, and usually targets stocks with market caps of less than $2 billion, letting investors diversify their funds among other kinds of small-cap equities. With a five-year annual return of 13.21%, this fund is a well-diversified fund with a long track record of success.

These examples highlight the fact that there are some astonishingly good mutual funds out there. If your advisor has you in the good ones, bravo! If not, you may need to have a talk.