It is never too late to invest in mutual funds for retirement. As such, if you plan to invest in some of the best funds, the Zacks Mutual Fund Rank can provide you with valuable guidance.

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.

Eaton Vance Tax-Managed Growth 1.1 I

(EITMX Quick QuoteEITMX - Free Report) : 0.47% expense ratio and 0.41% management fee. EITMX 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. EITMX has achieved five-year annual returns of an astounding 15.6%.

Janus Henderson Global Life Science I

(JFNIX Quick QuoteJFNIX - Free Report) is a stand out amongst its peers. JFNIX is part of the Sector - Health category, offering investors a focus on the healthcare industry, one of the largest sectors in the American economy. With five-year annualized performance of 12.33%, expense ratio of 0.77% and management fee of 0.64%, this diversified fund is an attractive buy with a strong history of performance.

Tortoise MLP & Pipeline Fund Investor

(TORTX Quick QuoteTORTX - Free Report) . Expense ratio: 1.17%. Management fee: 0.85%. Five year annual return: 14.01%. TORTX is a Sector - Energy mutual fund, which encompasses a wide range of vastly changing and vitally important industries throughout this massive global sector.

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.