Greater participation by consumers in saving and paying for their health care is shaking up the US health insurance industry, spawning not only once-in-a-generation opportunities but also increased competition from financial-services firms and benefits managers.

We estimate that annual pretax operating profits for health care-financial services products will grow to more than $10 billion by 2015; whether payers or financial institutions will grab the lion's share is anyone's guess. Changes in government regulations, technology, customer behavior in the face of increasing medical costs, and competition have blurred the boundaries between the health care and financial-services industries, creating a significant opportunity.

A major force behind this convergence is the recent US regulatory change that created tax-advantaged health savings accounts, which encourage consumers to take more responsibility for their own health care. The advent of HSAs has spurred the payers' cross-industry competitors into action. A range of financial-services companies—401(k) and individual-retirement-account (IRA) providers, banks, retail financial advisers, and life insurers—already provide savings, investment, credit, and payments products as well as financial advice. Now, greater consumer participation in paying for health care presents these companies with an opportunity, and many have introduced savings accounts and investment products to attract HSA assets.

But health...