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.

Boston Partners Global Equity Institutional (BPGIX Quick QuoteBPGIX - Free Report) has a 0.95% expense ratio and 0.9% management fee. BPGIX 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 With yearly returns of 12.45% over the last five years, this fund clearly wins.

T.Rowe Price Integrat US SMID Core (TQSMX). Expense ratio: 0.87%. Management fee: 0.63%. TQSMX is a Small Cap Blend mutual fund, and usually targets stocks with market caps of less than $2 billion, letting investors diversify their funds among other kinds of small-cap equities. This fund has managed to produce a robust 10.96% over the last five years.

MFS Blended Research Intl Eq A (BRXAX). Expense ratio: 0.74%. Management fee: 0.35%. Five year annual return: 13.33%. BRXAX is a part of the Non US - Equity fund category, many of which will focus across all cap levels, and will typically allocate their investments between emerging and developed markets.

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.