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.

How can you tell a good mutual fund from a bad one? It's pretty basic: if the fund is diversified, has low fees, and shows strong performance, it's a keeper. Of course, there's a wide range, but using the Zacks Mutual Fund Rank, we've found three mutual funds that would be great additions to any long-term retirement investors' portfolios.

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

If you are looking to diversify your portfolio, consider T.Rowe Price Integrated Glb Eq (TQGEX Quick QuoteTQGEX - Free Report) . TQGEX 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. This fund is a winner, boasting an expense ratio of 0.74%, management fee of 0.54%, and a five-year annualized return track record of 12.56%.

PGIM Jennison International Opportunity A (PWJAX Quick QuotePWJAX - Free Report) : 1.09% expense ratio and 0.81% management fee. PWJAX 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. With yearly returns of 12.83% over the last five years, PWJAX is an effectively diversified fund with a long reputation of solidly positive performance.

AB Value Adviser (ABVYX Quick QuoteABVYX - Free Report) . Expense ratio: 0.71%. Management fee: 0.55%. Five year annual return: 11.37%. ABVYX is a Large Cap Value fund. These funds invest in stocks with a market cap of $10 billion of more, but whose share prices do not reflect their intrinsic value.

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.