Share Class

AVERAGE ANNUAL TOTAL RETURNS

YTD 1-YR 3-YR INCEPTION*
A Shares (TLDAX)
Without sales charge1.37%1.16%1.07%1.22%
With sales charge-0.17%-0.37%0.56%0.82%
YTD 1-YR 3-YR INCEPTION*
I Shares (TLDIX)1.41%1.23%1.23%1.39%
YTD 1-YR 3-YR INCEPTION*
A Shares (TLDAX)
Without sales charge1.32%1.03%1.10%1.24%
With sales charge-0.21%-0.48%0.59%0.82%
YTD 1-YR 3-YR INCEPTION*
I Shares (TLDIX)1.35%1.19%1.26%1.41%

Returns for less than one year are not annualized.
*Inception date for Class A Shares 12/30/2013.

Returns for less than one year are not annualized.
*Inception date for Class I Shares 12/30/2013.

Performance data shown represents past performance and is no guarantee of future results. Investment return and principal value will fluctuate so shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than quoted.

The maximum sales charge for the Fund's A shares is 1.50%.

C shares include a 0.50% contingent deferred sales charge (CDSC) for the first year only.

There is no up-front sales charge for the I shares.

There is no up-front sales charge for class R shares.

FUND OPERATING EXPENSES — Class A Shares

Gross Annual Operating Expenses (as reported in the most recent Prospectus)1.74%
Net Annual Operating Expenses (as reported in the most recent Prospectus)0.70%
Actual Annual Operating Expenses (fiscal year to date, as of 9/30/2017)0.65%

Thornburg Investment Management and/or Thornburg Securities Corporation have contractually agreed to waive fees and reimburse expenses through at least April 10, 2018, so that actual expenses do not exceed the net expense ratio above.

Expense Ratios – Expressed as a percentage of total fund assets and include management fees and operating costs. Expense ratios fluctuate over time and the expense ratio in the prospectus may differ from the actual expense ratio. The fund's total return includes the deduction of expenses.

For more detailed information on fund expenses, please see the fund's prospectus.

FUND OPERATING EXPENSES — Class I Shares

Gross Annual Operating Expenses (as reported in the most recent Prospectus)1.18%
Net Annual Operating Expenses (as reported in the most recent Prospectus)0.50%
Actual Annual Operating Expenses (fiscal year to date, as of 9/30/2017)0.50%

Thornburg Investment Management and/or Thornburg Securities Corporation have contractually agreed to waive fees and reimburse expenses through at least April 10, 2018, so that actual expenses do not exceed the net expense ratio above.

Expense Ratios – Expressed as a percentage of total fund assets and include management fees and operating costs. Expense ratios fluctuate over time and the expense ratio in the prospectus may differ from the actual expense ratio. The fund's total return includes the deduction of expenses.

For more detailed information on fund expenses, please see the fund's prospectus.

MORNINGSTAR RATING

Overall Morningstar Rating among 460 Short-Term Bond funds, based on risk-adjusted returns for class A shares, using the fund's three-year rating: 3 stars among 460 funds, as of 10/31/2017.

Additional Rating and Ranking Information

To determine a fund's Morningstar Rating™, funds and other managed products with at least a three-year history are ranked in their categories by their Morningstar Risk-Adjusted Return scores. The top 10% receive 5 stars; the next 22.5%, 4 stars; the middle 35%, 3 stars; the next 22.5%, 2 stars; and the bottom 10% receive 1 star. The Risk-Adjusted Return accounts for variation in a managed product's monthly excess performance (excluding sales charges), placing more emphasis on downward variations and rewarding consistent performance. Other share classes may have different performance characteristics. © 2017 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.

MORNINGSTAR RATING

Overall Morningstar Rating among 460 Short-Term Bond funds, based on risk-adjusted returns for class I shares, using the fund's three-year rating: 3 stars among 460 funds, as of 10/31/2017.

Additional Rating and Ranking Information

To determine a fund's Morningstar Rating™, funds and other managed products with at least a three-year history are ranked in their categories by their Morningstar Risk-Adjusted Return scores. The top 10% receive 5 stars; the next 22.5%, 4 stars; the middle 35%, 3 stars; the next 22.5%, 2 stars; and the bottom 10% receive 1 star. The Risk-Adjusted Return accounts for variation in a managed product's monthly excess performance (excluding sales charges), placing more emphasis on downward variations and rewarding consistent performance. Other share classes may have different performance characteristics. © 2017 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.

LIPPER LEADER as of 9/30/2017 — Class A Shares

Preservation among 5777 funds
In the Short Investment Grade Debt category

The Fund rated a 5 for the three-year period for Preservation among 5777 funds.

Additional Rating and Ranking Information

Lipper ratings for Preservation reflect the funds’ historical loss avoidance relative to other funds within the fixed income asset class. The ratings are subject to change every month and are based on an equal-weighted average of percentile ranks for each metric over three-, five-, and ten-year periods (if applicable). The highest 20% of funds in each peer group are named Lipper Leader, or a score of 5, the next 20% receive a score of 4, the middle 20% are scored 3, the next 20% are scored 2, and the lowest 20% are scored 1. Lipper ratings are not intended to predict future results, and Lipper does not guarantee the accuracy of this information. More information is available at www.lipperweb.com. Thomson Reuters Copyright 2017, All Rights Reserved.

LIPPER LEADER as of 9/30/2017 — Class I Shares

Preservation among 5777 funds
In the Short Investment Grade Debt category

The Fund rated a 5 for the three-year period for Preservation among 5777 funds.

Additional Rating and Ranking Information

Lipper ratings for Preservation reflect the funds’ historical loss avoidance relative to other funds within the fixed income asset class. The ratings are subject to change every month and are based on an equal-weighted average of percentile ranks for each metric over three-, five-, and ten-year periods (if applicable). The highest 20% of funds in each peer group are named Lipper Leader, or a score of 5, the next 20% receive a score of 4, the middle 20% are scored 3, the next 20% are scored 2, and the lowest 20% are scored 1. Lipper ratings are not intended to predict future results, and Lipper does not guarantee the accuracy of this information. More information is available at www.lipperweb.com. Thomson Reuters Copyright 2017, All Rights Reserved.

30-day Yields With Sales Charge as of 10/31/2017 — Class A Shares

Annualized Distribution Yield1.47%
SEC Yield1.21%
Without the fee waivers and expense reimbursements described above the Annualized Distribution yield would have been 0.33%, and the SEC yield would have been 0.06%.

30-day Yields With Sales Charge as of 10/31/2017 — Class I Shares

Annualized Distribution Yield1.69%
SEC Yield1.43%
Without the fee waivers and expense reimbursements described above the Annualized Distribution yield would have been 1.15%, and the SEC yield would have been 0.88%.

Dividends and Capital Gains — Class A Shares

Dividend (paid Oct 31, 2017)$0.01591
Capital Gains (2017)None Paid

Dividends and Capital Gains — Class I Shares

Dividend (paid Oct 31, 2017)$0.01801
Capital Gains (2017)None Paid
Important Information
Before investing, carefully consider the Fund’s investment goals, risks, charges, and expenses. For a prospectus or summary prospectus containing this and other information, contact your financial advisor or visit our literature center. Read them carefully before investing.

Investments carry risks, including possible loss of principal. Portfolios investing in bonds have the same interest rate, inflation, and credit risks that are associated with the underlying bonds. The value of bonds will fluctuate relative to changes in interest rates, decreasing when interest rates rise. Unlike bonds, bond funds have ongoing fees and expenses. Investments in mortgage-backed securities (MBS) may bear additional risk. Investments in the Fund are not FDIC insured, nor are they bank deposits or guaranteed by a bank or any other entity.

Credit quality ratings for Thornburg’s global fixed income portfolios used ratings from Moody’s Investors Service. Where Moody’s ratings are not available, we have used S&P Global Ratings. Where neither rating is available, we have used ratings from other nationally recognized statistical rating organizations (NRSROs).

A bond credit rating assesses the financial ability of a debt issuer to make timely payments of principal and interest. Ratings of AAA (the highest), AA, A, and BBB are investment-grade quality. Ratings of BB, B, CCC, CC, C and D (the lowest) are considered below investment grade, speculative grade, or junk bonds.

The laddering strategy does not assure or guarantee better performance than a non-laddered portfolio and cannot eliminate the risk of investment losses.

Class I shares may not be available to all investors. Minimum investments for the I share class may be higher than those for other classes.

There is no guarantee that the Fund will meet its investment objectives.

Please see our glossary for a definition of terms.

Thornburg mutual funds are distributed by Thornburg Securities Corporation.

Thornburg Investment Management, Inc. mutual funds are sold through investment professionals including investment advisors, brokerage firms, bank trust departments, trust companies and certain other financial intermediaries. Thornburg Securities Corporation (TSC) does not act as broker of record for investors.