Senior Stock Plan Administrator

Join a team of brilliant, passionate innovators determined to transform healthcare. At BillionToOne, we've built a category-defining, publicly traded company on Nasdaq where transparency fuels trust, collaboration drives breakthroughs, and every contribution moves the needle on our mission to make life-changing diagnostics accessible to all. We don't just aim for incremental improvements; we build products that are 10x better than anything that exists today.

Our scientists, engineers, sales executives, and visionaries are united by an unwavering commitment to changing the standard of care in prenatal and cancer diagnostics. This is where cutting-edge science meets human compassion, and every innovation you contribute helps remove the fear of the unknown from some of life's most critical medical moments.

If you're driven by purpose, energized by innovation, and ready to help shape the future of precision medicine at scale, this is where you belong.

The Senior Stock Plan Administrator is responsible for the day-to-day administration of the Company's equity compensation program. This role provides hands-on support for equity operations, stock-based compensation accounting, compliance, reporting, and employee communications. The ideal candidate will partner closely with Legal, Payroll, Accounting, People Operations, and external service providers to ensure accurate, compliant, and timely execution of all equity-related activities. This position will report to the Company’s Controller.

• Maintain accurate equity data and records within equity administration systems and administer equity plan across the full equity lifecycle.
• Manage the end-to-end processing of equity transactions (grants, vesting, releases, exercises, cancellations, etc.) in the equity system.
• Coordinate Employee Stock Purchase Plan (ESPP) enrollment and purchase cycles and ensure accurate processing and reconciliations in collaboration with Payroll and Fidelity Equity system.

• Maintain and reconcile equity share pool balances; perform monthly reconciliations of shares outstanding and reserves with the transfer agent.
• Assist with equity plan setup, maintenance, and governance.
• Maintain accurate records and equity reconciliations and documentation to support internal/external audit readiness.
• Analyze and reconcile equity data, perform audits, and prepare / review all month-end journal entries.
• Support period-end close activities including stock-based compensation (SBC) accounting in accordance with ASC 718 and completing monthly and quarterly stock-based compensation close processes, ensuring accuracy in journal entries, accruals, and disclosures.
• Responsible for compliance with year end tax reporting requirements.

• Partner with Legal, Payroll, Accounting, and PeopleOps teams to ensure accurate, compliant, and timely execution of equity processes.
• Assist Payroll teams with equity reporting, tax compliance and reconciliation activities.
• Respond to employee inquiries regarding equity awards, vesting schedules, exercises, and taxation.

• Maintain accurate records and documentation to support audit readiness.
• Maintain SOX control documentation and perform assigned internal controls documentation to support SOX compliance.
• Respond to auditor requests inquiries in a timely manner.

• Document processes, SOX narratives and support continuous improvement initiatives.
• Identify opportunities to enhance equity processes and systems through integration and automation, improved controls, and workflow changes.

• Bachelor’s degree or equivalent experience (Business Administration, Finance, Accounting – plus)
• 5+ years of hands-on experience in equity compensation within a public company
• In-depth knowledge of equity platforms such as Fidelity Plan Sponsor Webstation^® (or equivalent systems) and managing platform processes end-to-end
• Strong understanding and experience of multiple types of equity (ISOs, NSOs, RSUs, ESPP) and related compliance, tax, and reporting requirements
• Strong experience supporting internal/external audits and ensuring compliance with SOX and ASC 718
• Experience managing complex reconciliations, close processes, and equity-related financial reporting
• Strong organization, analysis, and communication skills
• Ability to handle multiple priorities and meet deadlines
• Proficiency in Microsoft Excel, Word, and PowerPoint
• CEP certification or progress toward certification is a plus

Unity Complete™ is the only non-invasive prenatal screen capable of assessing fetal risk for both common recessive conditions and aneuploidies from a single maternal blood sample.
Unity Confirm™ enables non-invasive confirmation for high-risk screening results through the capture of intact circulating fetal cells using BillionToOne’s Fetal Cell Capture™ Technology.
Our Northstar® liquid biopsy test uniquely combines treatment selection with real-time monitoring, giving oncologists unprecedented precision in cancer care.

From $0 to $400M+ annualized revenue run-rate in just 6 years. In 2025, we completed one of the most successful IPOs for a medical diagnostics company, building on nearly $400M in private funding,including our $130M Series D in 2024 and backed by world-class investors including Hummingbird, Adams Street Partners, Neuberger Berman, Baillie Gifford, and Premji Invest.

Forbes named us one of America's Best Startup Employers for 2025 and we're Great Place to Work certified, with 100% of our people willing to go the extra mile, even as we've scaled to over 700 employees.

Headquartered in Menlo Park with facilities in Union City, CA, and a new lab opening in Austin, TX in 2027, we're continuing to push the boundaries of what's possible in molecular diagnostics. We're just getting started.

Ready to help us change the world, one molecule at a time? Learn more at billiontoone.com