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, most reliable way to judge a mutual fund's quality over time is by analyzing its performance, diversification, and fees. The Zacks Mutual Fund Rank, which covers over 19,000 mutual funds, has helped us identify three outstanding options that are perfect for any long-term investors' portfolios that is retirement-focused.

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

Deutsche Science and Technology Institutional (KTCIX Quick QuoteKTCIX - Free Report) has a 0.69% expense ratio and 0.45% management fee. With a much more diversified approach, KTCIX--part of the Sector - Tech mutual fund category--gives investors a way to own a stake in the notoriously risky tech sector. With yearly returns of 13.04% over the last five years, this fund clearly wins.

MFS Mass Investors Growth Stock I (MGTIX Quick QuoteMGTIX - Free Report) . Expense ratio: 0.46%. Management fee: 0.33%. MGTIX 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. This fund has managed to produce a robust 13.5% over the last five years.

Franklin Convertible Securities Adviser (FCSZX Quick QuoteFCSZX - Free Report) . Expense ratio: 0.58%. Management fee: 0.45%. Five year annual return: 11.35%. FCSZX is a Convertible Bonds mutual fund, and these funds are unique in the fixed income world; these securities have components of both fixed income and equity, making them hybrid securities.

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.