It is never too late to invest in mutual funds for retirement. As such, if you plan to invest in some of the best funds, the Zacks Mutual Fund Rank can provide you with valuable guidance.

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.

Fidelity Select Software & IT Services (FSCSX Quick QuoteFSCSX - Free Report) : 0.68% expense ratio and 0.52% management fee. FSCSX is a Sector - Tech mutual fund, allowing investors to own a stake in a notoriously volatile sector with a much more diversified approach. FSCSX has achieved five-year annual returns of an astounding 11.98%.

Neuberger Berman Guardian Adviser (NBGUX Quick QuoteNBGUX - Free Report) : 1.17% expense ratio and 0.88% management fee. NBGUX 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. NBGUX, with annual returns of 10.01% over the last five years, is a well-diversified fund with a long track record of success.

T. Rowe Price New Amer Growth I (PNAIX Quick QuotePNAIX - Free Report) . Expense ratio: 0.66%. Management fee: 0.63%. Five year annual return: 13.58%. PNAIX is a Large Cap Growth option; these mutual funds purchase stakes in numerous large U.S. companies that are expected to develop and grow at a faster rate than other large-cap stocks.

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.