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 investors' portfolios.

Let's learn about some of Zacks' highest ranked mutual funds with low fees you may want to consider.

Natixis Vaughan Nelson Mid Cap Y (VNVYX) has a 0.9% expense ratio and 0.75% management fee. VNVYX is a Mid Cap Value mutual funds that aims to target medium-sized companies that possess strong value and income opportunities for investors. With yearly returns of 12.87% over the last five years, this fund clearly wins.

FullerThaler Behav SmCap Grow Inv (FTXNX). Expense ratio: 1.29%. Management fee: 0.85%. FTXNX is a Small Cap Growth mutual fund and tends to feature small companies in up-and-coming industries and markets. This fund has managed to produce a robust 11.14% over the last five years.

First Eagle Rising Dividend R6 (FEFRX Quick QuoteFEFRX - Free Report) . Expense ratio: 0.63%. Management fee: 0.5%. Five year annual return: 13.48%. FEFRX, an All Cap Value option, is a type of mutual fund that buys stakes in companies in all three valuation categories

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.