Miller left Gehry Partners LLP to attend Columbia Business School in New York to study entrepreneurship and management. He was on the Dean's List throughout his time at the institution and served as a teaching assistant for the Greenhouse Entrepreneurship Program and the Launching New Ventures Program. During this time, he had the idea to launch a healthcare company that would assist employees comprehend and take advantage of flexible spending accounts (FSA). An FSA, which is arranged with an employer, allows employees to spend their income tax-free on medical expenses; however, as Miller discovered while working at Gehry Partners LLC, many employees didn't understand how the process worked and were foregoing the opportunity to cover healthcare-related expenses without paying taxes on the income used for this purpose.