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.

AB Large Cap Growth R (ABPRX Quick QuoteABPRX - Free Report) : 1.09% expense ratio and 0.48% management fee. ABPRX 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. ABPRX has achieved five-year annual returns of an astounding 10.83%.

Fidelity Convertible Securities (FCVSX Quick QuoteFCVSX - Free Report) : 0.74% expense ratio and 0.55% management fee. FCVSX is a Convertible Bonds fund, which are unique investment opportunities because they have both fixed income and equity components, making them hybrid securities. FCVSX, with annual returns of 10.68% over the last five years, is a well-diversified fund with a long track record of success.

Janus Henderson Global Technology Institutional (JGLTX Quick QuoteJGLTX - Free Report) is an attractive large-cap allocation. JGLTX is a Sector - Tech mutual fund, allowing investors to own a stake in a notoriously volatile sector with a much more diversified approach. JGLTX has an expense ratio of 0.74%, management fee of 0.64%, and annual returns of 12.78% over the past 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.