Flex is an online marketplace that helps shoppers discover and purchase health and wellness products using Health Savings Account (HSA) and Flexible Spending Account (FSA) funds. It brings together more than 1,000 eligible brands and thousands of approved products, with categories spanning ergonomics, fitness, footwear, home, nutrition, recovery, skincare, sleep, smart health, vision, and women’s health. The marketplace features products from brands such as Hyperice, OOFOS, Sleep Number, and Ballerina Farm, alongside offerings in areas including fitness equipment, pillows, supplements, air purification, and eyewear.

Customers can select Flex at checkout and pay with an HSA or FSA card, use a regular credit or debit card for reimbursement, or split a payment. Some products may require a Letter of Medical Necessity; Flex offers a chat-based telehealth consultation to help determine eligibility when needed. The service also provides information about account use and eligible purchases, and supports both consumers and businesses through its marketplace, consumer portal, and educational resources. Availability and savings depend on individual eligibility and circumstances.