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.

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

JPMorgan Large Cap Value Fund R5 (JLVRX Quick QuoteJLVRX - Free Report) has a 0.54% expense ratio and 0.4% management fee. JLVRX 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 yearly returns of 17.38% over the last five years, this fund clearly wins.

Nuveen Small-Cap Value Opps A (NSCAX): 1.2% expense ratio and 0.81% management fee. NSCAX is a Small Cap Value mutual fund, investing in small companies with stock market valuation less than $2 billion. NSCAX, with annual returns of 15.92% over the last five years, is a well-diversified fund with a long track record of success.

Thornburg International Value A (TGVAX): 1.16% expense ratio and 0.77% management fee. TGVAX is a Non US - Equity option, focusing their investments acoss emerging and developed markets, and can often extend across cap levels too. The fund is mainly invested in equities, has a long reputation of salutary performance, and has yearly returns of 12.34% over the last five years.

We hope that your investment advisor (if you use one) has you invested in one or all of the top-ranked mutual funds we've reviewed. But if that isn't the case, it might be time to have a conversation or reconsider this vitally important relationship.