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.

Let's break down some of the mutual funds with the top Zacks Mutual Fund Rank and the lowest fees.

Janus Henderson Research C

(JRACX Quick QuoteJRACX - Free Report) : 1.4% expense ratio and 0.48% management fee. JRACX 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. JRACX has achieved five-year annual returns of an astounding 16.66%.

Oak Ridge Dividend Growth I

(ORDNX Quick QuoteORDNX - Free Report) . Expense ratio: 0.97%. Management fee: 0.75%. ORDNX is part of the Large Cap Blend section, and these mutual funds most often invest in firms with a market capitalization of $10 billion or more. By investing in bigger companies, these funds offer more stability, and are often well-suited for investors with a "buy and hold" mindset. This fund has managed to produce a robust 12.16% over the last five years.

PGIM Jennison International Opportunity R6

(PWJQX Quick QuotePWJQX - Free Report) . Expense ratio: 0.84%. Management fee: 0.81%. Five year annual return: 11.58%. PWJQX is a part of the Non US - Equity fund category, many of which will focus across all cap levels, and will typically allocate their investments between emerging and developed markets.

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.