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.

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

Thornburg Investment Income Builder A (TIBAX): 1.1% expense ratio and 0.69% management fee. TIBAX is an Allocation Balanced mutual fund. Allocation Balanced funds look to invest across asset types, like stocks, bonds, and cash, and including precious metals or commodities is not unusual; these funds are mostly categorized by their respective asset allocation. TIBAX has achieved five-year annual returns of an astounding 14.86%.

Artisan Global Value Institutional (APHGX Quick QuoteAPHGX - Free Report) is a stand out amongst its peers. APHGX is a Global - Equity mutual fund. These funds invest in large markets like the U.S., Europe, and Japan, and operate with very few geographical limitations With five-year annualized performance of 12.09%, expense ratio of 1.01% and management fee of 0.98%, this diversified fund is an attractive buy with a strong history of performance.

State Street US Core Equity (SSAQX). Expense ratio: 0.14%. Management fee: 0.12%. Five year annual return: 13.34%. SSAQX 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.

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.