MIUIX Performance — MFS Municipal Intermediate Fund, Class I
Data updated: 2026-08-25
MIUIX returned +2.07% year to date and +6.61% over one year to Jun 2026. Annualised returns are +4.71% over 3 years and +1.77% over 5 years. The fund beat its Intermediate Municipal Bond category average: $100 invested three years ago grew to $115, against $111 for the category, and to $107 over one year, against $106. Volatility over the past three years was 4.84% a year. In the 12 months to Jun 2026 the fund took in a net $137.8M, and assets reached $435.63M.
MIUIX Growth of $100
What $100 invested in MFS Municipal Intermediate Fund grew to, compounded from monthly returns reported on SEC Form N-PORT, against the Intermediate Municipal Bond category average over the same months.
| Period | MIUIX | Category average |
|---|---|---|
| 1 year (Jul 2025 – Jun 2026) | $107 | $106 |
| 3 years (Jul 2023 – Jun 2026) | $115 | $111 |
| 5 years (Jul 2021 – Jun 2026) | $109 | $105 |
| Since data start (Apr 2021 – Jun 2026) | $110 | $106 |
MIUIX Trailing Returns
Total returns to Jun 2026, from SEC N-PORT.
| Period | Total return |
|---|---|
| YTD | +2.07% |
| 1 year | +6.61% |
| 3 years (annualised) | +4.71% |
| 5 years (annualised) | +1.77% |
MIUIX Annual Returns
Calendar-year total returns of MFS Municipal Intermediate Fund, compounded from monthly SEC N-PORT returns. Partial years show the months covered.
| Year | Total return |
|---|---|
| 2026 (Jan–Jun) | +2.07% |
| 2025 | +5.33% |
| 2024 | +3.00% |
| 2023 | +6.12% |
| 2022 | −7.20% |
| 2021 (Apr–Dec) | +0.54% |
MIUIX Monthly Returns
Monthly total returns as reported on SEC Form N-PORT.
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026 | +1.1% | +1.4% | −2.4% | +1.0% | +0.5% | +0.6% | — | — | — | — | — | — |
| 2025 | +0.5% | +1.1% | −1.4% | −0.5% | +0.2% | +0.9% | 0.0% | +0.9% | +1.8% | +1.1% | +0.3% | +0.3% |
| 2024 | +0.2% | +0.2% | +0.2% | −1.0% | −0.1% | +1.8% | +0.9% | +0.8% | +1.1% | −1.3% | +1.4% | −1.1% |
| 2023 | +2.9% | −2.3% | +2.1% | 0.0% | −1.0% | +0.7% | +0.3% | −0.9% | −2.3% | −1.1% | +5.3% | +2.5% |
| 2022 | −1.9% | −0.5% | −2.7% | −2.2% | +1.2% | −1.3% | +2.5% | −2.2% | −3.5% | −0.7% | +3.9% | +0.2% |
| 2021 | — | — | — | 0.0% | +0.3% | +0.1% | +0.8% | −0.2% | −0.7% | −0.3% | +0.4% | +0.1% |
MIUIX Risk
Risk measures from monthly returns over Jul 2023 – Jun 2026.
- 3-year volatility (annualised): 4.84%
- 3-year Sharpe ratio: 0.04 (vs 4.5% risk-free rate)
- Best month: +5.29% (Nov 2023)
- Worst month: −2.43% (Mar 2026)
MIUIX Fund Flows
Monthly money in and out of MFS Municipal Intermediate Fund, from SEC Form N-PORT.
- 12-month net flow: $137.8M
- 12-month gross sales (incl. reinvestments): $208.4M
- Sales ÷ redemptions: 2.95×
| Month | Sales | Redemptions | Net flow |
|---|---|---|---|
| Jun 2026 | $21.1M | $4.7M | $16.4M |
| May 2026 | $15.4M | $6.5M | $8.8M |
| Apr 2026 | $26.2M | $6.7M | $19.5M |
| Mar 2026 | $15.2M | $6.4M | $8.8M |
| Feb 2026 | $16.1M | $6.9M | $9.2M |
| Jan 2026 | $14.6M | $4.5M | $10.1M |
| Dec 2025 | $19.4M | $4.0M | $15.4M |
| Nov 2025 | $15.0M | $3.4M | $11.6M |
| Oct 2025 | $21.4M | $10.3M | $11.1M |
| Sep 2025 | $17.0M | $3.9M | $13.1M |
| Aug 2025 | $14.3M | $8.8M | $5.5M |
| Jul 2025 | $12.7M | $4.6M | $8.1M |
MIUIX Assets Under Management
Net assets of MFS Municipal Intermediate Fund by report date, from SEC N-PORT filings.
| Report date | Net assets |
|---|---|
| 2026-06-30 | $435.63M |
| 2026-03-31 | $385.94M |
| 2025-12-31 | $361.90M |
| 2025-09-30 | $321.01M |
| 2025-06-30 | $289.15M |
| 2025-03-31 | $242.46M |
| 2024-12-31 | $230.37M |
| 2024-09-30 | $201.49M |
| 2024-06-30 | $182.06M |
| 2024-03-31 | $176.14M |
| 2023-12-31 | $166.16M |
| 2023-09-30 | $143.10M |
For information only. Not investment advice: figures are as reported in SEC filings and may contain errors or be out of date. Past performance does not guarantee future results.