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.

AB Lg Cap Growth Z (APGZX Quick QuoteAPGZX - Free Report) has a 0.51% expense ratio and 0.48% management fee. APGZX 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. With yearly returns of 14.56% over the last five years, this fund clearly wins.

Hennessy Cornerstone Mid Cap 30 Investor (HFMDX Quick QuoteHFMDX - Free Report) : 1.36% expense ratio and 0.74% management fee. HFMDX is a Mid Cap Blend mutual fund, and usually features a portfolio with stocks of various styles and sizes, allowing for diversification within a strategy that focuses on mid cap companies. With yearly returns of 15.84% over the last five years, HFMDX is an effectively diversified fund with a long reputation of solidly positive performance.

Fidelity Convertible Securities (FCVSX Quick QuoteFCVSX - Free Report) . Expense ratio: 0.74%. Management fee: 0.55%. Five year annual return: 11.62%. FCVSX is a Convertible Bonds mutual fund, and these funds are unique in the fixed income world; these securities have components of both fixed income and equity, making them hybrid securities.

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.