A high rating does not necessarily imply that a fund had the best total performance or that the fund achieved positive results for that period. Morningstar rating is for the A share class only; other classes may have difference performance characteristics.  Please see the Performance tab for results as of the most recent month and quarter end.

The Morningstar Rating^TM for funds, or "star rating", is calculated for managed products (including mutual funds, variable annuity and variable life subaccounts, exchange-traded funds, closed-end funds, and separate accounts) with at least a three-year history. Exchange-traded funds and open-ended mutual funds are considered a single population for comparative purposes. It is calculated based on a Morningstar Risk-Adjusted Return measure that accounts for variation in a managed product's monthly excess performance, placing more emphasis on downward variations and rewarding consistent performance. The top 10% of products in each product category receive 5 stars, the next 22.5% receive 4 stars, the next 35% receive 3 stars, the next 22.5% receive 2 stars, and the bottom 10% receive 1 star. The Overall Morningstar Rating for a managed product is derived from a weighted average of the performance figures associated with its three-, five-, and 10-year (if applicable) Morningstar Rating metrics. The weights are: 100% three-year rating for 36-59 months of total returns, 60% five-year rating/40% three-year rating for 60-119 months of total returns, and 50% 10-year rating/30% five-year rating/20% three-year rating for 120 or more months of total returns. While the 10-year overall star rating formula seems to give the most weight to the 10-year period, the most recent three-year period actually has the greatest impact because it is included in all three rating periods.

The Morningstar Style Box^TM reveals a fund’s investment strategy. For fixed-income funds, the vertical axis of the Fixed Income Style Boxes shows the credit quality of the bonds owned (high, medium, or low) and the horizontal axis shows interest rate sensitivity (limited, moderate, or extensive) as measured by a bond’s effective duration.

Morningstar seeks credit rating information from fund companies on a periodic basis (e.g. quarterly). In compiling credit rating information Morningstar accepts credit ratings reported by fund companies that have been issued by all Nationally Recognized Statistical Rating Organizations (NRSROs). For a list of all NRSROs, please visit http://www.sec.gov/divisions/marketreg/ratingagency.htm. Additionally, Morningstar accepts foreign credit ratings from widely recognized or registered rating agencies. If two rating organizations/agencies have rated a security, fund companies are to report the lower rating; if three or more organizations/agencies have rated a security, fund companies are to report the median rating, and in cases where there are more than two organization/agency ratings and a median rating does not exist, fund companies are to use the lower of the two middle ratings. PLEASE NOTE: Morningstar, Inc. is not itself an NRSRO nor does it issue a credit rating on the fund. An NRSRO or rating agency ratings can change from time-to-time.

For credit quality, Morningstar combines the credit rating information provided by the fund companies with an average default rate calculation to come up with a weighted-average credit quality. The weighted-average credit quality is currently a letter that roughly corresponds to the scale used by a leading nationally recognized statistical rating organization (NRSRO). Bond funds are assigned a style box placement of “low”, “medium”, or “high” based on their average credit quality. Funds with a low credit quality are those whose weighted-average credit quality is determined to be less than “BBB–”; medium are those less than “AA–”, but greater or equal to “BBB–”; and high are those with a weighted average credit quality of “AA–” or higher. When classifying a bond portfolio, Morningstar first maps the NRSRO credit ratings of the underlying holdings to their respective default rates (as determined by Morningstar’s analysis of actual historical default rates). Morningstar then averages these default rates to determine the average default rate for the entire bond fund. Finally, Morningstar maps this average default rate to its corresponding credit rating along a convex curve. 

For interest-rate sensitivity, Morningstar obtains from fund companies the average effective duration. Generally, Morningstar classifies a fixed-income fund’s interest-rate sensitivity based on the effective duration of the Morningstar Core Bond Index (MCBI), which is currently three years. The classification of Limited will be assigned to those funds whose average effective duration is between 25% to 75% of MCBI’s average effective duration; funds whose average effective duration is between 75% to 125% of the MCBI will be classified as Moderate; and those that are at 125% or greater of the average effective duration of the MCBI will be classified as Extensive.  

© 2019 Morningstar, Inc. All rights reserved. The information contained herein: (1) is proprietary to Morningstar and/or its content providers; (2) may not be copied or distributed; and (3) is not warranted to be accurate, complete, or timely. Neither Morningstar nor its content providers are responsible for any damages or losses arising from any use of this information.  Past performance is no guarantee of future results.

³ Due to the high cost to shareholders of maintaining accounts with low balances, the transfer agent may, by redeeming shares, charge a semiannual fee of $10 if the value of shares in the account falls to an amount below the fund minimum.  See the Prospectus for more details. 

⁴ For more information on how to reduce your Sales Charges.

⁵ If you invest $1,000,000 or more in Class A Shares and redeem those shares within one year (the "one-year time period"), a deferred back-end sales charge of 1% will apply to the net asset value of those shares, with the net asset value measured at the time of purchase (or sale, if lower).