Low Duration Income Fund

The Thornburg Low Duration Income Fund (the "Fund") did not declare capital gain dividends during 2016.

Your dividends from the Fund must be reported on your 2016 federal income tax return. Listed below is a month-by-month percentage breakdown of sources of interest income earned by the Fund in 2016, including interest earned on U.S. government obligations. Some states and/or localities do not require you to pay state or local income tax on income derived from certain federal agency bonds. Please consult your tax advisor as to the extent and effect of such tax treatment in your state of residence.

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Average 2016

Corporate Securities

83.13% 82.92% 80.15% 79.81% 80.35% 80.29% 79.33% 79.66% 81.75% 83.49% 84.68% 85.02% 81.72%

Other Securities

2.00% 1.89% 1.64% 1.55% 1.49% 1.49% 1.39% 1.03% 1.01% 0.99% 0.99% 0.97% 1.37%

DIRECT U.S. OBLIGATIONS

U.S. Treasury

10.21% 10.69% 14.26% 14.93% 14.74% 14.85% 16.18% 15.73% 11.93% 10.38% 8.81% 7.93% 12.55%

Sub-total

10.21% 10.69% 14.26% 14.93% 14.74% 14.85% 16.18% 15.73% 11.93% 10.38% 8.81% 7.93% 12.55%

INDIRECT U.S. OBLIGATIONS

Federal Home Loan Mortgage Corporation

0.91% 0.87% 0.76% 0.72% 0.68% 0.64% 0.61% 1.26% 3.07% 2.83% 2.70% 2.85% 1.49%

Federal National Mortgage Association

0.89% 0.86% 0.74% 0.69% 0.64% 0.65% 0.58% 0.54% 0.51% 0.49% 0.48% 0.46% 0.63%

Other Government Agencies

2.86% 2.77% 2.45% 2.30% 2.10% 2.08% 1.91% 1.78% 1.73% 1.82% 2.34% 2.77% 2.24%

Sub-total

4.66% 4.50% 3.95% 3.71% 3.42% 3.37% 3.10% 3.58% 5.31% 5.14% 5.52% 6.08% 4.36%

Total

100.00%

100.00%

100.00%

100.00%

100.00%

100.00%

100.00%

100.00%

100.00%

100.00%

100.00%

100.00%

100.00%

Tax rules are complex. Please consult your tax advisor.

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 the Fund are not FDIC insured, nor are they bank deposits or guaranteed by a bank or any other entity.

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.