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.

Here are the funds that have achieved the Zacks Mutual Fund Rank #1 (Strong Buy) and have low fees.

Fidelity Convertible Securities (FCVSX): 0.74% expense ratio and 0.55% management fee. FCVSX is categorized as a Convertible Bonds fund, and in the fixed income world, these funds are quite unique. These types of securities are a hybrid, meaning they have components of both fixed income and equity. FCVSX has achieved five-year annual returns of an astounding 11.62%.

Red Oak Technology Select (ROGSX): 0.94% expense ratio and 0.74% management fee. ROGSX is a Sector - Tech mutual fund, allowing investors to own a stake in a notoriously volatile sector with a much more diversified approach. ROGSX, with annual returns of 13.82% over the last five years, is a well-diversified fund with a long track record of success.

Ivy Large Cap Growth N (ILGRX): 0.64% expense ratio and 0.61% management fee. ILGRX 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. The fund is mainly invested in equities, has a long reputation of salutary performance, and has yearly returns of 16.21% over the last 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.

Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report

Get Your Free (FCVSX): Fund Analysis Report

Get Your Free (ROGSX): Fund Analysis Report

Get Your Free (ILGRX): Fund Analysis Report

To read this article on Zacks.com click here.

Zacks Investment Research