Company: BLLN
Filing Date: 2025-10-17
Form Type: S-1/A
Source: 0001193125-25-242632
Chunk: 42

Company: BillionToOne, Inc.
Filing Date: 2025-10-17
Form: S-1/A
Chunk 42
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. If a third-party payor denies payment for testing, the reimbursement revenue for our testing could decline. If a third-party payor successfully proves that payment for prior testing was in breach
of contract or otherwise contrary to law, they may recoup payment or bring legal action to do so, which amounts could be significant and would adversely impact our results of operations, and it may decrease reimbursement going forward. We may also
decide to negotiate and settle with a third-party payor in order to resolve an allegation of overpayment.

In addition, third-party reimbursement for our tests is
based on professional society practice guidelines around the tests performed by our products. These guidelines are issued by medical professional societies in the

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prenatal and oncology clinical areas, such as ACOG for our prenatal tests and the National Comprehensive Cancer Network (NCCN) for our oncology tests. While ACOG guidelines generally acknowledge
that NIPT is the most sensitive screening option for, and/or are generally supportive of NIPT in, average-risk pregnancies in addition to high-risk pregnancies, and NCCN is generally supportive of comprehensive genomic profiling tests, a category
that includes Northstar Select, not all of our current tests are covered under practice guidelines, and we cannot predict whether our future tests will be covered by such guidelines. Further, medical professional societies, at times, change their
guidelines. In that case, our tests may no longer be covered, which could negatively affect our ability to obtain reimbursement, or the tests offered by our competitors may be more highly preferred by the ordering providers as a result of a change
in a medical guideline.

While our primary prenatal tests, such as carrier testing and aneuploidy, have broad guideline support and payor coverage, certain add-ons
of our prenatal tests, such as the 22q microdeletion component of UNITY Aneuploidy NIPT or the single-gene NIPT component of our UNITY Fetal Risk Screen, are covered by only a small number of insurance companies, due to more limited, or
non-existent, medical guideline support. In oncology, Northstar Select is covered broadly by Medicare, but more narrowly for only certain indications (e.g., lung cancer) by commercial third-party payors. Northstar Response is currently neither
covered by Medicare nor by many insurance companies.

In that case, our tests may no longer be covered, which could negatively affect our ability to obtain
reimbursement, or the tests offered by our competitors may be