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.

Baird Midcap Institutional (BMDIX Quick QuoteBMDIX - Free Report) : 0.81% expense ratio and 0.75% management fee. BMDIX is a Mid Cap Growth mutual fund. These funds aim to target companies with a market capitalization between $2 billion and $10 billion that are also expected to exhibit more extensive growth opportunities for investors than their peers. BMDIX has achieved five-year annual returns of an astounding 11%.

VALIC Company I Large Cap Growth Fund (VLCGX Quick QuoteVLCGX - Free Report) : 0.74% expense ratio and 0.64% management fee. VLCGX 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. VLCGX, with annual returns of 12.26% over the last five years, is a well-diversified fund with a long track record of success.

Fidelity Advisor Semiconductors M (FELTX Quick QuoteFELTX - Free Report) . Expense ratio: 1.25%. Management fee: 0.52%. Five year annual return: 14.94%. FELTX is a Sector - Tech mutual fund, allowing investors to own a stake in a notoriously volatile sector with a much more diversified approach.

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.