Build the future
of HSA/FSA payments

Flex is more than just a workplace, it’s a community of ambitious, collaborative thinkers redefining what’s possible.

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Our story

Flex was founded to solve a simple but costly problem: making it easy for health and wellness brands to accept HSA and FSA payments online. For years, only giants like Amazon and Walmart could process these payments at checkout, leaving smaller merchants — and their customers — to deal with frustrating reimbursement paperwork.

Our technology verifies product eligibility in real time, handles split payments for eligible and non-eligible items, and can even issue Letters of Medical Necessity during checkout. With $150 billion in annual HSA/FSA spending potential, we’re giving brands the tools to unlock new revenue and making it easier for consumers to use the benefits they’ve earned.

"Stay curious and embrace the unknown — growth comes from challenging yourself and learning from the people around you."

Sam O'Keefe | Co-Founder & CEO

Benefits at Flex

We believe great work starts with a great workplace. From comprehensive healthcare to flexible time off and equity ownership, our benefits are designed to support your wellbeing, growth, and life outside of work.

Healthcare

Comprehensive medical, dental, and vision coverage to keep you and your family healthy.

Remote-First

Work from wherever you’re most productive. Our team is distributed across the U.S.

401(k)

A simple, seamless way to save for retirement and invest confidently in your future.

Quarterly Offsites

Gather in person every quarter for collaboration, connection, and team-building.

Unlimited PTO

Take the time you need with unlimited paid time off—and we encourage you to actually use it.