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 Advisor Stock Select Allocation Cap M (FSJHX Quick QuoteFSJHX - Free Report) : 1.13% expense ratio and 0.46% management fee. FSJHX 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. FSJHX has achieved five-year annual returns of an astounding 13.59%.

O'Shaughnessey MarketLeadersValue I (OFVIX Quick QuoteOFVIX - Free Report) . Expense ratio: 0.53%. Management fee: 0.4%. OFVIX 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 11.07% over the last five years.

PGIM Jennison Health Sciences A (PHLAX Quick QuotePHLAX - Free Report) : 1.15% expense ratio and 0.73% management fee. PHLAX is part of the Sector - Health category, offering investors a focus on the healthcare industry, one of the largest sectors in the American economy. The fund is mainly invested in equities, has a long reputation of salutary performance, and has yearly returns of 11.6% over the last five years.

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.