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 Brown Advisory Sustainable Growth I (BAFWX Quick QuoteBAFWX - Free Report) . BAFWX 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. This fund is a winner, boasting an expense ratio of 0.63%, management fee of 0.55%, and a five-year annualized return track record of 12.95%.

Fidelity Advisor Technology I (FATIX Quick QuoteFATIX - Free Report) . Expense ratio: 0.71%. Management fee: 0.52%. FATIX is a Sector - Tech mutual fund, allowing investors to own a stake in a notoriously volatile sector with a much more diversified approach. This fund has managed to produce a robust 14.18% over the last five years.

Neuberger Berman Small Cap Growth Adviser (NBMVX Quick QuoteNBMVX - Free Report) : 1.4% expense ratio and 1.23% management fee. NBMVX is one of many Small Cap Growth mutual funds; these funds tend to create their portfolios around stocks with market capitalization of less than $2 billion. With a five-year annual return of 10.28%, this fund is a well-diversified fund with a long track record of success.

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.