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 take a look at some of our top-ranked mutual funds with the lowest fees.

Athena Value I (ATVIX Quick QuoteATVIX - Free Report) has a 1.25% expense ratio and 1% management fee. ATVIX is a Mid Cap Value fund, which usually invests in companies with a stock market valuation between $2 billion and $10 billion. With yearly returns of 8.66% over the last five years, this fund clearly wins.

Fidelity Balanced Fund (FBALX Quick QuoteFBALX - Free Report) is a stand out amongst its peers. FBALX is classified as an Allocation Balanced fund, which seeks to invest in a balance of asset types, like stocks, bonds, and cash, and including precious metals or commodities is not unusual. With five-year annualized performance of 11.24%, expense ratio of 0.5% and management fee of 0.38%, this diversified fund is an attractive buy with a strong history of performance.

Vanguard Health Care Admiral (VGHAX Quick QuoteVGHAX - Free Report) : 0.31% expense ratio and 0.28% management fee. VGHAX is part of the Sector - Health category, offering investors a focus on the healthcare industry, one of the largest sectors in the American economy. With a five-year annual return of 9.32%, this fund is a well-diversified fund with a long track record of success.

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.