If you're invested in any of the funds in our "Magnificent Retirement Mutual Funds" list, congratulations on owning some of the best managed and top-performing mutual funds. If you are lucky enough to discover our list of Top-Ranked Funds for the first time, it's never too late to start investing with the best, especially when it comes to your retirement.

The easiest, most reliable way to judge a mutual fund's quality over time is by analyzing its performance, diversification, and fees. Our Zacks Rank 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.

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

Matthews China Small Companies Investor (MCSMX Quick QuoteMCSMX - Free Report) : 1.42% expense ratio and 1% management fee. MCSMX is a Pacific Rim - Equity mutual fund; these funds typically invest in companies throughout the dominant export-focused markets of Hong Kong, Singapore, Taiwan, and Korea. With annual returns of 18.73% over the last five years, this fund is a winner.

MSIF Advantage Portfolio I (MPAIX Quick QuoteMPAIX - Free Report) . Expense ratio: 0.84%. Management fee: 0.65%. MPAIX 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 20.09% over the last five years.

Franklin Small-Mid Cap Growth Adviser (FSGAX Quick QuoteFSGAX - Free Report) . Expense ratio: 0.62%. Management fee: 0.46%. Five year annual return: 11.56%. FSGAX is a Small Cap Growth mutual fund and tends to feature small companies in up-and-coming industries and markets.

We hope that your investment advisor (if you use one) has you invested in one or all of the top-ranked mutual funds we've reviewed. But if that isn't the case, it might be time to have a conversation or reconsider this vitally important relationship.

Do You Know the Top 9 Retirement Investing Mistakes?

Investing in underperforming mutual funds is just one of the key errors that can derail your retirement plans.

To learn more, read our just-released report: 9 Retirement Mistakes You Need to Avoid.