It is never too late to invest in mutual funds for retirement. As such, if you plan to invest in some of the best funds, the Zacks Mutual Fund Rank can provide you with valuable guidance.

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.

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

First Eagle Overseas R6 (FEORX Quick QuoteFEORX - Free Report) has a 0.79% expense ratio and 0.75% management fee. FEORX is a Non US - Equity option, focusing their investments acoss emerging and developed markets, and can often extend across cap levels too. With yearly returns of 10.2% over the last five years, this fund clearly wins.

Sterling Capital Bhv LgCapVal Eq R6 (STRAX) is a stand out amongst its peers. STRAX 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. With five-year annualized performance of 14.09%, expense ratio of 0.68% and management fee of 0.45%, this diversified fund is an attractive buy with a strong history of performance.

Wasatch Global Value Investor (FMIEX): 1.1% expense ratio and 0.9% management fee. FMIEX 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 The fund is mainly invested in equities, has a long reputation of salutary performance, and has yearly returns of 11.66% over the last five years.

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.