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 take a look at some of our top-ranked mutual funds with the lowest fees.

Lord Abbett Growth Leaders F (LGLFX Quick QuoteLGLFX - Free Report) has a 0.64% expense ratio and 0.51% management fee. LGLFX 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 yearly returns of 7.53% over the last five years, this fund clearly wins.

PIMCO RAE US Small I2 (PMJPX): 0.61% expense ratio and 0.6% management fee. PMJPX is a Small Cap Value mutual fund option, which typically invest in companies with market caps under $2 billion. PMJPX, with annual returns of 12.85% over the last five years, is a well-diversified fund with a long track record of success.

T. Rowe Price Science & Technology Adviser (PASTX): 1.05% expense ratio and 0.63% management fee. PASTX is a Sector - Tech mutual fund, allowing investors to own a stake in a notoriously volatile sector with a much more diversified approach. The fund is mainly invested in equities, has a long reputation of salutary performance, and has yearly returns of 14.17% over the last five years.

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.