Fund Evaluator:
Thornburg Intermediate Municipal A (THIMX)
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Best Performing in Muni National Interm Over the Last Year
| 6.7% | Sit Tax-Free Income (SNTIX) |
| 4.6% | Goldman Sachs Dynamic Municipal Inc Inv (GUIRX) |
| 4.6% | Putnam Strategic Intermediate Muncpl Y (PAMYX) |
| 4.3% | Brown Advisory Tax Exempt Bond Investor (BIAEX) |
| 4.2% | Victory Tax Exempt Intermediate-Term (USATX) |
Fund Details
Thornburg Intermediate Municipal A Overview
Thornburg Intermediate Municipal A (THIMX) is an actively managed Municipal Bond Muni National Interm fund. Thornburg launched the fund in 1991.
The investment seeks to obtain as high a level of current income exempt from federal individual income tax as is consistent, in the view of the fund's investment advisor, with preservation of capital; to reduce expected changes in its share price compared to long-term bond portfolios is the secondary objective. The fund pursues its primary goal by investing principally in a laddered maturity portfolio of municipal obligations issued by states and state agencies, local governments and their agencies, and by United States territories and possessions.
About Thornburg Intermediate Municipal A (THIMX)
There are 3 members of the management team with an average tenure of 5.06 years: Eve Lando (2020), David Ashley (2019), Craig Mauermann (2025). Management tenure is more important for actively managed funds than passive index funds.
The fund has 2 primary benchmarks: ICE BofA US Muni TR USD index with a weighting of 100% and ICE BofA 3-15Y US Muni TR USD index with a weighting of 100%. Thornburg Intermediate Municipal A has 639 securities in its portfolio. The top 10 holdings constitute 8.9% of the fund’s assets. The fund meets the SEC requirement of being classified as a diversified fund. The fund is not considered to have an ESG focus with its investment selection and management.
Thornburg Intermediate Municipal A is part of the Fixed Income global asset class and is within the Municipal Bond fund group. Thornburg Intermediate Municipal A has 0.1% of its portfolio invested in foreign issues. The overall assets allocated to domestic stock is 0.0%. There is 0.0% allocated to foreign stock, and 0.0% is allocated to preferred stocks. The bond allocation as a percentage of total assets is 99.8% (99.7% domestic bond, 0.1% foreign bond and 0.0% convertible bond). Thornburg Intermediate Municipal A has 0.2% of the portfolio in cash.
Assets Under Management
The fund has $223 million in total assets, which is below the $1 billion average for the Muni National Interm category. Normally, lower assets under management translates to higher average expense ratios, and greater total assets are desired. However, for some investment categories, such as small-cap investing, it may be difficult for the manager to fully employ the desired active strategy if assets grow too large or too quickly.
THIMX Performance and Fees
The expense ratio measures how much of a fund’s assets are used for administrative expenses and operating expenses, including adviser fees and fees for the transfer agent and custodial services. The Thornburg Intermediate Municipal A expense ratio is above average compared to funds in the Muni National Interm category. Thornburg Intermediate Municipal A has an expense ratio of 0.73%, which is 6% higher than its category average, making the fund expense ratio grade a D. While it is difficult to predict returns, it is known that high annual expense ratios reduce your rate of return, and excessive fees are difficult to overcome. Active management normally comes with higher expense ratios than passive index management. Certain investment categories such as small company and foreign also normally have higher expense ratios. It is best to compare fund expense ratios against the category averages for meaningful assessments.
High portfolio turnover can translate to higher expenses and lower aftertax returns. A portfolio turnover rate cannot be currently calculated for Thornburg Intermediate Municipal A. By way of comparison, the average portfolio turnover is 38% for the Muni National Interm category.
Recently, in the month of August 2026, Thornburg Intermediate Municipal A returned -0.2%, which earned it a grade of F, as the Muni National Interm category had an average return of -0.1%. The letter grades of A, B, C, D and F are based upon relative rankings within the investment category. A grade of A, for example, would indicate that the return is in the highest 20% for that time period compared to all funds in that category.
Thornburg Intermediate Municipal A has a trailing yield of 3.74%, which is above the 3.27% category average. The fund normally distributes its income monthly and its capital gains annually.
It’s natural to seek the best-performing investments, but you must consider the relationship between risk and return and the impact of costs and taxes on your realized returns.
Thornburg Intermediate Municipal A Grades
Year to date, the fund has returned 0.5%, 0.2 percentage points better than the category, which translates into a grade of B. The fund has returned 3.8% over the past year (grade of C), 3.6% over the past three years (grade of B) and 1.1% per year over the past five years (grade of A) and 1.6% per year over the past 10 years (grade of D).
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THIMX Trailing NAV Total Returns Data as of 8/31/26
| Last Month |
Last Quarter |
Ann'l. 1Yr |
Ann'l. 3Yr |
Ann'l. 5Yr |
Ann'l. 10Yr |
|
| THIMX Return (NAV) | -0.2% | -0.9% | 3.8% | 3.6% | 1.1% | 1.6% |
| THIMX Grade | F | B | C | B | A | D |
| +/- Category | -0.1% | 0.1% | 0.1% | 0.2% | 0.4% | -0.0% |
| Muni National Interm Avg | -0.1% | -1.0% | 3.7% | 3.5% | 0.6% | 1.7% |
| THIMX Tax Cost Ratio | na | na | 0.0% | 0.0% | 0.0% | 0.0% |
THIMX Annual NAV Total ReturnsData as of 8/31/26
| 2026 | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | |
| THIMX Return (NAV) | 0.5% | 4.7% | 1.8% | 5.5% | -6.4% | 1.0% | 3.8% | 5.6% | 0.6% | 3.6% | -0.5% |
| THIMX Grade | B | B | C | D | A | D | D | F | D | F | D |
| +/- Category | 0.2% | 0.5% | -0.1% | -0.3% | 1.8% | -0.7% | -0.5% | -1.0% | -0.2% | -1.1% | -0.3% |
| Muni National Interm Avg | 0.3% | 4.2% | 2.0% | 5.7% | -8.2% | 1.7% | 4.3% | 6.7% | 0.8% | 4.7% | -0.2% |
| Risk Measures | |
| Standard Deviation: | 4.1% |
| Total Risk Index: | 0.34 - Low |
| Category Risk Index: | 0.88 - Low |
| Category Risk Grade: | A (18% Rank) |
| Beta: | 0.73 |
| R-Squared: | 99% |
| Leveraged Fund: | No |
| Inverse Fund: | No |
| Portfolio Characteristics | |
| Equity Investment Style: | na |
| Bond Investment Style: | High Quality Moderate Sensitivity |
| Yield: | 3.7% |
| Dividend Distribution: | Monthly |
| Cap Gains Distribution: | Annually |
| Total Assets: | $1263 Mil |
| Fund Total Assets: | $ 224 Mil |
| Share Class Type: | A |
| Portfolio Turnover: | na |
Management Team
| Number of Managers: 3 | |||
| Longest Tenure: 7.6 years | |||
| Average Tenure: 5.1 years | |||
| Managers (Year): Ashley David (2019), Lando Eve (2020), Mauermann Craig (2025) | |||
Portfolio Composition (as of 7/31/26)
| # of Holdings: | 639 |
| % in Top 10 Holdings: | 8.9% |
| Fund is Non-Diversified: | No |
| % in Foreign Issues: | 0.1% |
Portfolio Allocation |
|
| Domestic Stock: | 0.0% |
| Foreign Stock: | 0.0% |
| Preferred Stock: | 0.0% |
| Domestic Bond: | 99.7% |
| Foreign Bond: | 0.1% |
| Convertible Bond: | 0.0% |
| Other: | 0.0% |
| Cash: | 0.2% |
Purchase Information
| Fund Family: | Thornburg |
| Phone Number: | 800-847-0200 |
| Website: | www.thornburg.com |
| Status: | Open |
| Inception Date: | July 22, 1991 |
| Min. Initial Purchase: | $1,000 |
| Min. Initial IRA Purchase: | $ 0 |
| True No-Load: | No |
| Front Load Maximum: | 2.00% |
| Deferred Charge Maximum: | 0.00% |
| Redemption Charge Maximum: | 0.00% |
| 12b-1 Fee: | 0.25% |
Expenses and Fees | |
| Expense Ratio (%): | 0.73% ( Rating : Above Avg ) |
| Category Average Expense Ratio (%): | 0.69% |
| Share Class: | Thornburg Intermediate Municipal A |
| Min. Subsequent Purchase: | $ 0 |
| Min. Subsequent IRA Purchase: | $ 0 |
