David Tonaszuck, NSSA® & IRMAACP™ Advisor · Marshfield, MA

David Tonaszuck has always believed that hard work and faith go hand in hand. He and his wife Anne, married for over 32 years, make their home in Duxbury, Massachusetts, where both are deeply rooted in their church and community. Their shared commitment to serving others is central to their lives—a value that shines through in everything David does.

Guided by Proverbs 14:23—“There is profit in hard work”—David sees his work as more than just numbers and charts. For him, profit means making a real impact in people’s lives, especially as they navigate the complexities of financial and retirement income planning. He’s passionate about helping clients find clarity and peace of mind, no matter how uncertain the waters may seem.

David’s gift for making sense of numbers led him to the Massachusetts Institute of Technology, where he earned a joint Master of Science degree from the School of Engineering and the Sloan School of Management. His coursework combined advanced engineering with management, laying the groundwork for a career that would blend analytical rigor with thoughtful strategy.

David Tonaszuck holds both the NSSA® designation in Social Security planning and the IRMAA Certified Planner designation, reflecting advanced training in retirement income and Medicare cost planning.

Since entering the financial services industry in the early 2000s, David has earned a reputation as an internationally recognized market technician and portfolio manager. He’s helped clients across the U.S. and around the world—including as far as India—build strong, resilient investment portfolios. Over time, though, his focus has shifted from growing wealth to helping clients protect what they’ve built. That’s the heart behind Oak and Shield Wealth Management: providing the strength and resiliency needed to engineer retirement income strategies that truly last.

At Oak and Shield, David believes the real challenge isn’t just in accumulating assets—it’s in the “decumulation phase,” when systematic withdrawal strategies become essential. His approach centers on prevention through strategic planning, rather than correction after the fact. By acting as a strategist, protector, and partner, David offers more than advice—he offers a plan clients can rely on.

David’s expertise in “advanced income engineering” means his clients benefit from carefully designed strategies for income visibility, Social Security and Medicare coordination, and long-term retirement sustainability. He’s known for building plans that work not just in theory, but when life takes an unexpected turn.

A life of service extends beyond the office. David is active in his local parish, a strong supporter of the Archdiocese of Boston, and a familiar face in community projects and events. He and Anne have been blessed with three wonderful children.

To better serve his clients, David has pursued extensive professional education, earning the following credentials:

• NSSA® Social Security Certification, National Social Security Advisors

• IRMAACPTM Medicare Premium Surcharges and Planning Strategies Certification, National Social Security Advisors

• CSSTM Certified Social Security and Medicare Specialist, Institute of Business & Finance

• CRCSTM Certified Roth IRA Conversion Specialist , Wealth Preservation Institute

• CASTM Certified Annuities Specialist, Institute of Business & Finance

• CESTM Certified Estate and Trust Planning Specialist, Institute of Business & Finance

• CLTC® Certified in Long-Term Care, Certification for Long-Term Care

David isn’t finished learning—he’s currently working toward the Certified Financial Planner (CFP®) designation and IRS-Approved Enrolled Agent (EA) status. For David, financial planning is about more than getting the numbers right. It’s about building relationships, offering guidance, and giving clients the confidence to enjoy their retirement years. If you’re looking for a partner who brings integrity, expertise, and a genuine desire to help, you’ll find it at Oak and Shield Wealth Management.

Contact David