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 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.

JPMorgan Mid Cap Growth Fund R6 (JMGMX Quick QuoteJMGMX - Free Report) has a 0.7% expense ratio and 0.65% management fee. JMGMX is a Mid Cap Growth mutual fund. These funds aim to target companies with a market capitalization between $2 billion and $10 billion that are also expected to exhibit more extensive growth opportunities for investors than their peers. With yearly returns of 11.89% over the last five years, this fund clearly wins.

Janus Henderson Global Life Science D (JNGLX Quick QuoteJNGLX - Free Report) : 0.8% expense ratio and 0.64% management fee. JNGLX is classified as a Sector - Health fund. Healthcare is one of the biggest sectors of the American economy, and these kinds of mutual funds provide a great opportunity to invest in this industry. With yearly returns of 10.02% over the last five years, JNGLX is an effectively diversified fund with a long reputation of solidly positive performance.

Loomis Sayles Growth Fund A (LGRRX Quick QuoteLGRRX - Free Report) : 0.92% expense ratio and 0.5% management fee. LGRRX is a part of the Large Cap Growth mutual fund category, which invest in many large U.S. companies that are expected to grow much faster compared to other large-cap stocks. The fund is mainly invested in equities, has a long reputation of salutary performance, and has yearly returns of 14.23% 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.