Deposit Mortality Index Now Available from Prismm to Help Banks and Credit Unions Understand and Protect Against Deposit Risk

- New index estimates $1.5 trillion in deposits will leave U.S. financial institutions over the next ten years as account holders pass away; every federally insured bank and credit union has been scored -

NEWARK, Del.--(BUSINESS WIRE)--Prismm (Wunderwood Corporation d/b/a Prismm), an estate orchestration infrastructure platform for banks and credit unions, today announced the availability of its Deposit Mortality Index™ (DMI), a first-of-its-kind measurement designed to give banks and credit unions a deeper understanding of the strength, stability and future trajectory of their deposit portfolios. All 8,429 federally insured U.S. banks and credit unions have been scored. The index was created by Prismm Founder and CEO Martha Sylla Underwood, author of The Death of Deposits.

Visit getprismm.com/dmi to learn more or to request your institution's report.

The Deposit Mortality Index helps banks and credit unions identify hidden maturity risk within their deposit base and uncover opportunities to strengthen relationships before assets leave the institution. Built using Prismm's proprietary methodology, the report transforms public data, including FDIC branch deposits, Census demographics, Federal Reserve holdings data and SSA life tables, into actionable intelligence that financial institutions can use to inform strategic planning.

Unlike traditional deposit reporting that focuses on balances and historical trends, the Deposit Mortality Index measures the resilience of a financial institution's deposit base by evaluating factors that influence whether deposits are likely to remain with the institution as ownership changes over time. The result is a practical benchmark for understanding future deposit risk and identifying new retention opportunities. An estimated $124 trillion in U.S. household wealth will transfer through 2048, and roughly 70 percent of inherited balances leave the incumbent institution.

“Banks and credit unions have never had a way to measure the future health of their deposits until now,” said Martha Sylla Underwood, Founder and CEO of Prismm. “The Deposit Mortality Index gives executives a completely new perspective by revealing risks and opportunities that traditional reporting simply cannot see. As wealth changes hands over the coming decades, institutions that understand the maturity of their deposits will be far better positioned to preserve deposits and retain relationships for generations to come.”

Each DMI report delivers a composite score, national tier, and national rank among all scored institutions, along with a clear view of the growth, demographic and portfolio dynamics shaping an institution's deposit outlook. The analysis highlights where mortality-driven runoff may emerge, which underlying factors are most contributing to risk and which actions can have the greatest impact, giving leadership teams a focused starting point for planning without requiring them to parse complex actuarial or public-data inputs on their own.

The index was calibrated once on the full national distribution and frozen, so scores are comparable across institutions and over time. The complete methodology, assumptions register, and change log are available on request.

Download The State of Deposit Mortality 2026, the inaugural study behind the index. Institution reports are $799 each at getprismm.com/dmi.

About Prismm

Prismm is a fintech company providing inheritance infrastructure for banks, credit unions and wealth management partners. Its platform integrates with existing systems to guide the organization, preparation and transfer of assets during life transitions. By bringing structure to a historically fragmented process, Prismm enables financial institutions to retain deposits, strengthen client relationships and improve continuity across generations. Learn more at getprismm.com.

Deposit Mortality Index, DMI, and DMI Verified are trademarks of Wunderwood Corporation d/b/a Prismm.