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, most reliable way to judge a mutual fund's quality over time is by analyzing its performance, diversification, and fees. The Zacks Mutual Fund Rank, which covers over 19,000 mutual funds, has helped us identify three outstanding options that are perfect for any long-term investors' portfolios that is retirement-focused.

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

If you are looking to diversify your portfolio, consider Hood River Small Cap Growth Institutional (HRSMX Quick QuoteHRSMX - Free Report) . HRSMX is a Small Cap Growth mutual fund and tends to feature small companies in up-and-coming industries and markets. This fund is a winner, boasting an expense ratio of 1.06%, management fee of 0.9%, and a five-year annualized return track record of 11.19%.

JPMorgan Large Cap Growth C (OLGCX Quick QuoteOLGCX - Free Report) . Expense ratio: 1.44%. Management fee: 0.45%. OLGCX 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. This fund has managed to produce a robust 14.1% over the last five years.

Deutsche Science and Technology S (KTCSX Quick QuoteKTCSX - Free Report) . Expense ratio: 0.7%. Management fee: 0.45%. Five year annual return: 11.4%. KTCSX is part of the Sector - Tech mutual fund category that invests in technology and lets investors own a stake in a notoriously volatile sector, but with a much more diversified approach.

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.