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.

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

Lord Abbett Growth Leaders A (LGLAX Quick QuoteLGLAX - Free Report) : 0.91% expense ratio and 0.51% management fee. LGLAX 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. LGLAX has achieved five-year annual returns of an astounding 12.12%.

AllianzGI Convertible Fund IS (ANNPX Quick QuoteANNPX - Free Report) : 0.71% expense ratio and 0.57% management fee. ANNPX 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. ANNPX, with annual returns of 11.65% over the last five years, is a well-diversified fund with a long track record of success.

Oppenheimer Discovery I (ODIIX Quick QuoteODIIX - Free Report) is an attractive large-cap allocation. ODIIX is one of many Small Cap Growth mutual funds; these funds tend to create their portfolios around stocks with market capitalization of less than $2 billion. ODIIX has an expense ratio of 0.65%, management fee of 0.59%, and annual returns of 10.86% over the past five years.

There you have it. If your financial advisor had you put your money into any of our top-ranked funds, then they've got you covered. If not, you may need to talk.