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 take a look at some of our top-ranked mutual funds with the lowest fees.

LSV Global Managed Volatility Instl (LSVFX): 0.75% expense ratio and 0.6% management fee. LSVFX is a Global - Equity mutual fund. These funds invest in large markets like the U.S., Europe, and Japan, and operate with very few geographical limitations LSVFX has achieved five-year annual returns of an astounding 10.69%.

American Funds Inv Co of Amer F3 (FFICX Quick QuoteFFICX - Free Report) : 0.26% expense ratio and 0.23% management fee. FFICX is classified as a Large Cap Blend fund. More often than not, Large Cap Blend mutual funds invest in companies with a market cap of over $10 billion. Buying stakes in bigger companies offer these funds more stability, and are well-suited for investors with a "buy and hold" mindset. FFICX, with annual returns of 13.03% over the last five years, is a well-diversified fund with a long track record of success.

Virtus Silvant Large Cap Growth Stock A (STCIX). Expense ratio: 1.03%. Management fee: 0.7%. Five year annual return: 12.33%. STCIX 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.