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.

Fidelity Advisor Capital Development O (FDETX Quick QuoteFDETX - Free Report) : 0.56% expense ratio and 0.53% management fee. FDETX is a Large Cap Blend fund, targeting companies with market caps of over $10 billion. These funds offer investors a stability, and are perfect for people with a "buy and hold" mindset. With annual returns of 11.22% over the last five years, this fund is a winner.

JPMorgan Intrepid Growth Fund R2 (JIGZX Quick QuoteJIGZX - Free Report) : 1.09% expense ratio and 0.3% management fee. JIGZX 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. JIGZX, with annual returns of 12.21% over the last five years, is a well-diversified fund with a long track record of success.

Columbia Dividend Income I3 (CDDYX Quick QuoteCDDYX - Free Report) . Expense ratio: 0.55%. Management fee: 0.53%. Five year annual return: 10.72%. CDDYX 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.

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.