LEGAL AND REGULATORY PROCEEDINGS	9 Months Ended
LEGAL AND REGULATORY PROCEEDINGS	Sep. 30, 2025
Commitments and Contingencies Disclosure [Abstract]
LEGAL AND REGULATORY PROCEEDINGS	LEGAL AND REGULATORY PROCEEDINGS The Company is subject to various claims, complaints, regulatory proceedings, and legal actions that arise from time to time in the ordinary course of business. Federal Securities Class Actions On November 11, 2023, the first of three securities class action complaints was filed against Illumina and certain of its current and former executive officers in the United States District Court for the Southern District of California. The first-filed case is captioned Kangas v. Illumina, Inc. et al., the second-filed case is captioned Roy v. Illumina, Inc. et al., and the third-filed case is captioned Louisiana Sheriffs’ Pension & Relief Fund v. Illumina, Inc. et al. (collectively, the “Actions”). The complaints generally allege, among other things, that defendants made materially false and misleading statements and omitted material facts relating to Illumina’s acquisition of Grail. The complaints seek unspecified damages, interest, fees, and costs. On January 9, 2024, four movants filed motions to consolidate the Actions and to appoint a lead plaintiff (“Lead Plaintiff Motions”). On April 11, 2024, the Court issued an order consolidating the Actions into a single action (captioned in re Illumina, Inc. Securities Litigation No. 23-cv-2082-LL-MMP), and appointed Universal-Investment-Gesellschaft mbH, UI BVK Kapitalverwaltungsgesellschaft mbH, and ACATIS Investment Kapitalverwaltungsgesellschaft mbH as lead plaintiffs. (the “Lead Plaintiffs”). On June 21, 2024, the Lead Plaintiffs filed a consolidated amended complaint. The amended complaint alleges that GRAIL, in addition to Illumina, and certain of their respective current and former directors and others violated sections 10(b) and 20(a) of the Securities Exchange Act and SEC Rule 10b-5 in connection with Illumina's acquisition of GRAIL and disclosures concerning the same. GRAIL has an indemnification obligation for certain current and former directors and officers involved in the matter pursuant to indemnification agreements entered into by these individuals and GRAIL. On September 13, 2024 the plaintiffs further amended the complaint. On November 12, 2024, the Company moved to dismiss Lead Plaintiffs’ second amended complaint for failure to state a claim under Sections 10(b) and 20(a) of the Exchange Act. Lead Plaintiffs filed their opposition to the motion to dismiss on December 20, 2024, and the Company filed its reply in support of its motion to dismiss on February 3, 2025. On September 26, 2025, the court granted the motion to dismiss for failure to state a claim with leave to amend, and ordered the plaintiffs to file an amended complaint, if any, by October 27, 2025. On October 27, 2025, the Lead Plaintiffs filed their third amended complaint. The Company denies the allegations in the complaints and intends to vigorously defend the litigation. In light of the fact that the lawsuits are in an early stage, the Company cannot predict the ultimate outcome of the suits. Other Legal Matters Legal matters include various claims, complaints, and legal actions that arise from time to time. In addition to direct involvement in legal matters, the Company has entered into indemnification agreements with each of its current and former directors, executive officers, and certain other officers to provide these directors and officers, and has certain indemnification obligations under the Company’s charter and bylaws to these individuals, which may give rise to liability for the Company even if the Company is not directly named. The Company has indemnification obligations in respect of the Actions and with respect to other legal matters that may arise, or have arisen, from time to time. There can be no assurance that existing or future legal proceedings arising in the ordinary course of business or otherwise will not have a material adverse effect on the Company’s business, financial position, results of operations, or cash flows. The Company is involved in various lawsuits and claims arising in the ordinary course of business, including actions with respect to employment matters. In connection with these matters, the Company assesses, on a regular basis, the probability and range of possible loss based on the developments in these matters. A liability is recorded in the unaudited condensed consolidated financial statements if it is believed to be probable that a loss has been incurred and the amount of the loss can be reasonably estimated. Since litigation is inherently unpredictable and unfavorable resolutions could occur, assessing contingencies is highly subjective and requires judgments about future events. The Company regularly reviews outstanding legal matters to determine the adequacy of the liabilities accrued and related disclosures. The Company may change its estimates if its assessment of the various factors changes and the amount of ultimate loss may differ from estimates, resulting in a material effect on the Company’s business, financial condition, results of operations, and/or cash flows. As of September 30, 2025, the Company is unable to estimate a range of possible loss in excess of the amounts accrued. Contingencies Contingencies primarily correspond to claims arising in the ordinary course of business. If necessary, these contingencies will be accrued, to the extent believed to be reasonably estimable to resolve the matter. The accrued contingency amounts are included in other current liabilities. Should the Company not be able to secure the terms it expects, these estimates may change and will be recognized in the period in which they are identified. In connection with the Spin-Off, Illumina provided the Company with disposal funding in the amount of $932.3 million in accordance with the Separation and Distribution Agreement, which was subject to a clawback feature that lapsed on September 24, 2025. On June 21, 2024, in connection with the Spin-Off, Illumina and the Company also entered into the Tax Matters Agreement to govern the respective rights, responsibilities and obligations of Illumina and the Company after the Spin-Off with respect to all tax matters and will include restrictions to preserve the tax-free status of the Distribution. The Tax Matters Agreement included a number of restrictions on the Company to preserve the intended tax treatment of the Spin-Off. Breach of any covenant or representation contained in the Tax Matters Agreement will result in liability to specific separation taxes. As of September 30, 2025, as it was not probable that the Company will breach the agreement, no contingent liability was recorded in connection with the Tax Matters Agreement.