Ready to redefine what's possible in molecular diagnostics?

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.

With over 700 employees, half a million patients helped, and one of the most successful IPOs in medical diagnostics history behind us, we're just getting started. 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.

We are looking for a field-based professional Oncology Medical Science Liaison (MSL) with scientific and clinical expertise in oncology to support our oncology portfolio of liquid biopsy products. The Medical Science Liaison (MSL), Oncology is a remote position and reports to our Associate Director, Medical Affairs.

Region: US Central Time (Texas, Oklahoma)

Responsibilities:

• Serve as a key liaison to Health Care Providers (HCPs) in the oncology space regarding liquid biopsy and BillionToOne products
• Serve as a key member of the BillionToOne Oncology Medical Affairs team
• Develop and maintain relationships with key opinion leaders (KOLs) by engaging in scientific exchange with medical and scientific partners
• Support commercial team by providing impactful information that enhances the value and proper use of BillionToOne products
• Respond to HCP customer inquiries to provide focused and balanced clinical and scientific information that supports the appropriate use of or clinically differentiates BillionToOne's products and services
• Contribute to development of provider and patient educational products
• Adhere to internal standard processes and comply with regulatory and compliance requirements
• Other duties as may be assigned

Qualifications:

• Advanced degree in a related science or health discipline
• 2+ years of experience as a Medical Science Liaison or similar position in oncology, diagnostic experience preferred
• Expertise in discussing scientific content and context to multiple audiences
• Excellent communication and interpersonal skills
• Ability to travel up to 70% 

Benefits And Perks:

• Working alongside brilliant, kind, passionate and dedicated colleagues, in an empowering environment, toward a global vision, striving for a future in which transformative molecular diagnostics can help millions of patients
• Open, transparent culture that includes weekly Town Hall meetings
• The ability to indirectly or directly change the lives of hundreds of thousands patients
• Multiple medical benefit options; employee premiums paid 100% of select plans, dependents covered up to 80%
• Extremely generous Family Bonding Leave for new parents (16 weeks, paid at 100%)
• Supplemental fertility benefits coverage 
• Retirement savings program including a 4% Company match
• Increase paid time off with increased tenure
• Latest and greatest hardware (laptop, lab equipment, facilities)

At BillionToOne, we are proud to offer a combination of a (1) base pay range (actual amount offered is based on experience and salary/equity options split that the candidate chooses), (2) generous equity options offering, (3) corporate bonus program, on top of (4) industry leading company benefits (free healthcare options, 401k match, very generous fully paid parental leave, etc.).

For this position, we offer a total compensation package of $228,281, including a base pay range of $163,681 - $184,801 per year.

BillionToOne is an equal opportunity employer. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.

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About BillionToOne

BillionToOne is a next-generation molecular diagnostics company on a mission to make powerful, accurate diagnostic tests accessible to everyone. Our revolutionary QCT molecular counting technology enhances disease detection resolution by over a thousandfold using cell-free DNA,a breakthrough that has already transformed the lives of over half a million patients worldwide.

Our Impact

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. Our Northstar® liquid biopsy test uniquely combines treatment selection with real-time monitoring, giving oncologists unprecedented precision in cancer care.

Our Growth

From $0 to $150M+ in Annual Recurring Revenue in just five 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.

Our Recognition

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.

Our Future

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