SCHEDULE 13D/A

MFS HIGH YIELD MUN TR

Common Stock · CUSIP: 59318E102

Event date: 2025-12-12

Reporting persons may disclose overlapping interests. Their amounts are shown individually and are not added into a filing total.

Filing-level shares

Unavailable

Percent of class

Unavailable

• Bulldog Investors, LLPReported CIK 0001504304

  Shares: 3,671,536.00 · Class: 14.4%

• Phillip Goldstein

  Shares: 4,007,921.00 · Class: 15.72%

• Andrew Dakos

  Shares: 3,561,726.00 · Class: 13.97%

Amounts are as disclosed in this filing. Schedule type alone does not establish investment intent.