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.

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

Fidelity Fund : 0.46% expense ratio and 0.31% management fee. FFIDX is a Large Cap Blend fund, targeting companies with market caps of over $10 billion. These funds offer investors a stability, and are perfect for people with a "buy and hold" mindset. FFIDX has achieved five-year annual returns of an astounding 11.28%.

Hennessy Cornerstone Mid Cap 30 Investor (HFMDX Quick QuoteHFMDX - Free Report) : 1.35% expense ratio and 0.74% management fee. HFMDX is a Mid Cap Blend mutual fund that typically features a portfolio filled with stocks of various sizes and styles; it allows for a diversification strategy focusing on companies with market caps between $2 billion and $10 billion. With yearly returns of 11.08% over the last five years, HFMDX is an effectively diversified fund with a long reputation of solidly positive performance.

MFS Mass Investors Growth Stock R6 (MIGNX Quick QuoteMIGNX - Free Report) . Expense ratio: 0.37%. Management fee: 0.33%. Five year annual return: 13.6%. MIGNX 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.

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.