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.

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

Goldman Sachs Small Cap Value Insights IR (GTTTX Quick QuoteGTTTX - Free Report) : 0.96% expense ratio and 0.8% management fee. GTTTX is a Small Cap Value fund, and these funds are known for investing in companies with market caps under $2 billion. GTTTX has achieved five-year annual returns of an astounding 7.98%.

John Hancock Disciplined Value A (JVLAX Quick QuoteJVLAX - Free Report) . Expense ratio: 1.02%. Management fee: 0.61%. JVLAX 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. This fund has managed to produce a robust 10.31% over the last five years.

Fidelity OTC Portfolio K (FOCKX Quick QuoteFOCKX - Free Report) : 0.69% expense ratio and 0.64% management fee. FOCKX 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. The fund is mainly invested in equities, has a long reputation of salutary performance, and has yearly returns of 18.45% 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.