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.

Baron Durable Advantage Instl (BDAIX Quick QuoteBDAIX - Free Report) : 0.7% expense ratio and 0.65% management fee. BDAIX 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 16.87% over the last five years, this fund is a winner.

JHancock International Dynamic Gr I (JIJIX) is a stand out amongst its peers. JIJIX is a Non US - Equity fund. Many of these funds like to allocate across emerging and developed markets, and will often focus on all cap levels. With five-year annualized performance of 9.22%, expense ratio of 0.94% and management fee of 0.8%, this diversified fund is an attractive buy with a strong history of performance.

Fidelity Natural Resources (FNARX) is an attractive large-cap allocation. FNARX is a Sector - Energy mutual fund, which encompasses a wide range of vastly changing and vitally important industries throughout this massive global sector. FNARX has an expense ratio of 0.69%, management fee of 0.67%, and annual returns of 24.19% over the past five years.

We hope that your investment advisor (if you use one) has you invested in one or all of the top-ranked mutual funds we've reviewed. But if that isn't the case, it might be time to have a conversation or reconsider this vitally important relationship.