There is never a wrong time to invest in mutual funds for retirement. So, if you're still looking for the best mutual funds, the Zacks Mutual Fund Rank can be a great guide.

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.

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

JPMorgan Intrepid Value Fund R5 (JIVRX Quick QuoteJIVRX - Free Report) : 0.44% expense ratio and 0.3% management fee. JIVRX is a Large Cap Value mutual fund, which invests in stocks with a market cap of $10 billion of more, but whose share prices do not reflect their intrinsic value. With annual returns of 9.62% over the last five years, this fund is a winner.

AQR Small Cap Multi-Style N (QSMNX Quick QuoteQSMNX - Free Report) . Expense ratio: 0.85%. Management fee: 0.45%. QSMNX is a Small Cap Blend mutual fund, allowing investors a way to diversify their funds among various types of small-cap stocks. This fund has managed to produce a robust 8.91% over the last five years.

American Funds Growth and Income Portfolio R5 (RGNFX Quick QuoteRGNFX - Free Report) : 0.06% expense ratio and 0% management fee. RGNFX is classified as a Large Cap Blend fund. More often than not, Large Cap Blend mutual funds invest in companies with a market cap of over $10 billion. Buying stakes in bigger companies offer these funds more stability, and are well-suited for investors with a "buy and hold" mindset. With a five-year annual return of 8.85%, 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.