Mark A. Brostowski

Mark Brostowski, 63, of Palm Beach Gardens, Florida, passed away on February 2, 2026 after a brief illness.

Mark was born on August 20, 1962, in Detroit, Michigan, and grew up in Dearborn Heights. He was the beloved son of the late Virginia Kopec Brostowski and the late Ronald Brostowski. He is survived by his sisters, Veronica (Robert) Stein and Valerie (Anthony) Ferguson.

Mark shared 32 wonderful years of marriage with his wife and best friend, Maribeth Brostowski. Together, they raised two children, Ginger (Robert Sieber) Brostowski and Ian Brostowski, who were the greatest pride and joy of his life. Mark was loved and adored by his 11 nieces and nephews and 4 grand nieces and nephews who loved spending time with him. Family and friends were always at the center of Mark’s life, and he cherished the relationships he built and nurtured over the years.

He graduated from Michigan State University in 1985 and earned his MBA from the University of Notre Dame in 1987. Mark built a distinguished career in finance, holding positions at both Solomon Brothers and BankBoston, before creating and building Regiment Capital. His vision, work ethic, leadership, and integrity left a lasting impact.

Mark will be remembered for his warmth, humor, sharp intellect, generosity and unwavering dedication to those he loved. While he will be so missed, his legacy will live on through the family he cherished, the friendships he valued, and the many lives he touched.

Family and friends will honor and remember Mark’s life by gathering for a Funeral Mass in St. Cecilia Church, 18 Belvedere Street, Boston, MA, on Thursday, February 5, 2026, at 2:30 p.m.

In lieu of flowers, please do not send flowers, the family suggests donations be made in Mark’s memory to Nativity Preparatory School, 39 Lamartine Street, Jamaica Plain, MA 02130, or online at https://www.nativityboston.org/