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.

Brandes Emerging Markets Value I (BEMIX Quick QuoteBEMIX - Free Report) : 1.12% expense ratio and 0.95% management fee. BEMIX is a Non US - Equity fund. Many of these funds like to allocate across emerging and developed markets, and will often focus on all cap levels. BEMIX has achieved five-year annual returns of an astounding 10.56%.

Fidelity Advisor Growth Opportunit (FAOFX) is a stand out amongst its peers. FAOFX is a part of the Large Cap Growth mutual fund category, which invest in many large U.S. companies that are expected to grow much faster compared to other large-cap stocks. With five-year annualized performance of 13.91%, expense ratio of 0.01% and management fee of 0%, this diversified fund is an attractive buy with a strong history of performance.

JPMorgan Equity Income Fund A (OIEIX): 0.95% expense ratio and 0.4% management fee. OIEIX is part of the Large Cap Blend section, and these mutual funds most often invest in firms with a market capitalization of $10 billion or more. By investing in bigger companies, these funds offer more stability, and are often well-suited for investors with a "buy and hold" mindset. With a five-year annual return of 11.76%, this fund is a well-diversified fund with a long track record of success.

These examples highlight the fact that there are some astonishingly good mutual funds out there. If your advisor has you in the good ones, bravo! If not, you may need to have a talk.