Company: BLLN
Filing Date: 2025-08-11
Form Type: DRS/A
Source: 0000950123-25-007483
Chunk: 221

Company: BillionToOne, Inc.
Filing Date: 2025-08-11
Form: DRS/A
Chunk 221
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 validated the clinical utility of our tests through peer-reviewed publications and real-world data. Reimbursement sources and status We receive reimbursement from several distinct sources:

| • |     | Commercial third-party payors, including insurance companies and health maintenance organizations |

| • |     | Government payors, state Medicaid programs, and Medicare |

| • |     | Employee benefits health plans |

| • |     | Individual patients, who represent a small amount of our revenue |

Commercial third-party payors We have significantly expanded our in-networkstatus with commercial insurers, including several of the largest national payors. We expect this in-networkexpansion to continue driving higher ASPs and enhance revenue predictability, due to the contracts establishing agreed-upon rates. Beyond our contracted rate agreements, we submit claims for reimbursement and receive associated payments from commercial insurers on a non-contractedbasis as necessary. The amount of reimbursement allowed and collected outside of network contract rates with commercial insurers is subject to greater variability and less predictability. In prenatal, our carrier and aneuploidy tests are broadly covered by most major insurance providers, and we have broad reimbursement for tests we provide. Our sgNIPT and fetal antigen NIPT have variable coverage, with certain payors providing reimbursement, creating opportunities for ASP growth as coverage expands. For our oncology products, Northstar Select has gained coverage from several commercial insurers. Northstar Response, while newer to market, is already reimbursed by certain commercial insurers, achieving a level of ASP that already provides positive contribution margins. 169

Medicare We have obtained Medicare coverage for both our prenatal and oncology testing services. In April 2025, our Northstar Select test received a positive coverage decision and Z-codethrough the MolDX program administered by Palmetto GBA. For our prenatal tests, Medicare provides coverage for patients who meet the Medicare eligibility criteria; however, this represents a very small portion of our prenatal test volume given the demographics of pregnant patients. For our oncology portfolio, Medicare coverage is crucial given the higher prevalence of cancer in the Medicare-eligible population. We continue to advance our evidence development strategy for Northstar Response, which requires additional clinical validity and utility data for Medicare coverage. Our flagship “NORTH” study, along with other ongoing clinical studies, is designed to generate the evidence necessary for Medicare coverage, initially focusing on immunotherapy and immunotherapy-combination therapy applications. Medicaid We have enrolled in over 40 state Medicaid programs across the United States. These enrollments are critical for our prenatal test ASPs