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

Fidelity Focused Stock Fund

(FTQGX Quick QuoteFTQGX - Free Report) : 0.61% expense ratio and 0.34% management fee. FTQGX is a Large Cap Growth mutual fund, and these funds invest in many large U.S. firms that are projected to grow at a faster rate than their large-cap peers. With annual returns of 17.7% over the last five years, this fund is a winner.

Janus Henderson Global Technology D

(JNGTX Quick QuoteJNGTX - Free Report) . Expense ratio: 0.78%. Management fee: 0.64%. With a much more diversified approach, JNGTX--part of the Sector - Tech mutual fund category--gives investors a way to own a stake in the notoriously risky tech sector. This fund has managed to produce a robust 19.7% over the last five years.

T. Rowe Price Value Adviser

(PAVLX Quick QuotePAVLX - Free Report) : 0.95% expense ratio and 0.56% management fee. PAVLX 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. With a five-year annual return of 12.07%, 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.