Our "Magnificent Retirement Mutual Funds" list includes some of the best managed and best performing funds around. If you're already invested in these, congratulations! But if you're just now discovering them, don't worry. When it comes to your retirement, it's never too late to start investing in the best.

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.

Let's take a look at some of the highest Zacks Ranked mutual funds with the lowest fees.

T. Rowe Price New America Growth Adviser (PAWAX Quick QuotePAWAX - Free Report) has a 1.05% expense ratio and 0.64% management fee. PAWAX is a part of the Large Cap Growth mutual fund category, which invest in many large U.S. companies that are expected to grow much faster compared to other large-cap stocks. With yearly returns of 16.23% over the last five years, this fund clearly wins.

AB Discovery Growth R (CHCRX Quick QuoteCHCRX - Free Report) : 1.39% expense ratio and 0.61% management fee. CHCRX is a Mid Cap Growth mutual fund. These mutual funds choose companies with a stock market valuation between $2 billion and $10 billion. With yearly returns of 12% over the last five years, CHCRX is an effectively diversified fund with a long reputation of solidly positive performance.

Lord Abbett Convertible Fund F (LBFFX Quick QuoteLBFFX - Free Report) : 0.96% expense ratio and 0.7% management fee. LBFFX 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. With a five-year annual return of 10.86%, 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.

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.