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.

John Hancock Disciplined Value R4 (JDVFX Quick QuoteJDVFX - Free Report) : 0.9% expense ratio and 0.61% management fee. JDVFX is a Large Cap Value mutual fund, which invests in stocks with a market cap of $10 billion of more, but whose share prices do not reflect their intrinsic value. JDVFX has achieved five-year annual returns of an astounding 11.86%.

BlackRock Eurofund I (MAEFX Quick QuoteMAEFX - Free Report) : 1.04% expense ratio and 0.75% management fee. MAEFX is a Europe - Equity mutual fund investing in stocks across the vast European continent. With yearly returns of 10.41% over the last five years, MAEFX is an effectively diversified fund with a long reputation of solidly positive performance.

Columbia Large Cap Enhanced Core A (NMIAX Quick QuoteNMIAX - Free Report) . Expense ratio: 0.83%. Management fee: 0.75%. Five year annual return: 14.59%. NMIAX 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.

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.