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.

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 OTC Portfolio (FOCPX Quick QuoteFOCPX - Free Report) . FOCPX 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 0.84%, management fee of 0.68%, and a five-year annualized return track record of 11.56%.

Oppenheimer Discovery Y (ODIYX Quick QuoteODIYX - Free Report) : 0.76% expense ratio and 0.59% management fee. ODIYX is a Small Cap Growth mutual fund and tends to feature small companies in up-and-coming industries and markets. With yearly returns of 10.69% over the last five years, ODIYX is an effectively diversified fund with a long reputation of solidly positive performance.

Neuberger Berman Guardian R3 (NGDRX Quick QuoteNGDRX - Free Report) . Expense ratio: 1.36%. Management fee: 0.74%. Five year annual return: 10.85%. NGDRX 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.

There you have it. If your financial advisor had you put your money into any of our top-ranked funds, then they've got you covered. If not, you may need to talk.