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

Janus Henderson Research T (JAMRX Quick QuoteJAMRX - Free Report) : 0.9% expense ratio and 0.53% management fee. JAMRX 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. JAMRX has achieved five-year annual returns of an astounding 15.02%.

Jensen Quality Value Fund I (JNVIX). Expense ratio: 0.82%. Management fee: 0.65%. JNVIX 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. This fund has managed to produce a robust 7.43% over the last five years.

DWS Equity Sector Strategy C (SUPCX): 1.49% expense ratio and 0.28% management fee. SUPCX is a part of the Allocation Balanced fund category; these funds like to invest in a variety of asset types, finding a balance between stocks, bonds, cash, and sometimes even precious metals and commodities; they are mostly categorized by their respective asset allocation. With a five-year annual return of 12.04%, 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.