Founded in 2014, Sentinel Capital Group was built on the conviction that lower middle market businesses are best served by patient, operationally engaged capital. The firm partners with management teams to accelerate growth while preserving company culture.
About SENTINEL
A Decade of Disciplined Investing
Our Team
Experienced practitioners bringing sector perspective, disciplined execution, and long-term client partnership.
Marcus J. Sentinel
Founder & Managing Partner
25 years in private equity and investment banking with deep industrial sector expertise.
Katherine L. Adler
Partner
15 years investing in lower middle market businesses with operational value creation focus.
Core Principles
Operational Partnership
We invest behind management teams and provide strategic support without replacing leadership.
Long-Term Orientation
Flexible hold periods aligned with building real value, not exit timelines.
Founder-Friendly Terms
We structure deals that protect seller equity, employee continuity, and brand legacy.
Operating Model
Coverage Model
Senior professionals remain directly involved from kickoff through close.
Governance Cadence
Weekly operating calls and milestone gates keep decisions moving.
Reporting Standard
Concise, decision-focused updates tailored for principals and boards.