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.

Here are the funds that have achieved the Zacks Mutual Fund Rank #1 (Strong Buy) and have low fees.

Great-WestMultiMgrLgCapGrowIns (MXGSX Quick QuoteMXGSX - Free Report) : 0.65% expense ratio and 0.64% management fee. MXGSX 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. With annual returns of 12.84% over the last five years, this fund is a winner.

ProFunds Tech UltraSector Investor (TEPIX Quick QuoteTEPIX - Free Report) . Expense ratio: 1.43%. Management fee: 0.75%. With a much more diversified approach, TEPIX--part of the Sector - Tech mutual fund category--gives investors a way to own a stake in the notoriously risky tech sector. This fund has managed to produce a robust 17.92% over the last five years.

Bridgeway Small Cap Value N (BRSVX Quick QuoteBRSVX - Free Report) . Expense ratio: 0.83%. Management fee: 0.61%. Five year annual return: 10.05%. BRSVX is a Small Cap Value mutual fund option, which typically invest in companies with market caps under $2 billion.

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.