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 easiest way to judge a mutual fund's quality over time is by analyzing its performance, diversification, and fees. Using the Zacks Mutual Fund Rank of over 19,000 mutual funds, we've identified three outstanding mutual funds that are ideally suited to help long-term investors pursue and achieve their retirement investing goals.

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

Vanguard Capital Opportunity Inv (VHCOX): 0.4% expense ratio and 0.39% management fee. VHCOX is a Large Cap Growth option; these mutual funds purchase stakes in numerous large U.S. companies that are expected to develop and grow at a faster rate than other large-cap stocks. With annual returns of 14.76% over the last five years, this fund is a winner.

Emerald Growth Fund Institutional (FGROX Quick QuoteFGROX - Free Report) is a stand out amongst its peers. FGROX is a Small Cap Growth mutual fund and tends to feature small companies in up-and-coming industries and markets. With five-year annualized performance of 13.79%, expense ratio of 0.75% and management fee of 0.61%, this diversified fund is an attractive buy with a strong history of performance.

Harbor International Core Retire (HAORX): 0.77% expense ratio and 0.75% management fee. HAORX is a Non US - Equity option, focusing their investments acoss emerging and developed markets, and can often extend across cap levels too. With a five-year annual return of 11.84%, this fund is a well-diversified fund with a long track record of success.

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.