LEGAL PROCEEDINGS, COMMITMENTS, AND CONTINGENCIES	9 Months Ended
Sep. 30, 2026
Commitments and Contingencies Disclosure [Abstract]
LEGAL PROCEEDINGS, COMMITMENTS, AND CONTINGENCIES	LEGAL PROCEEDINGS, COMMITMENTS, AND CONTINGENCIES 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. Illumina 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 “Illumina 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 Illumina Actions and to appoint a lead plaintiff (“Lead Plaintiff Motions”). On April 11, 2024, the Court issued an order consolidating the Illumina 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 alleged 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 the U.S. Securities and Exchange Commission (the “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 the Lead Plaintiffs’ second amended complaint for failure to state a claim under Sections 10(b) and 20(a) of the Exchange Act. On September 26, 2025, the court granted the motion to dismiss for failure to state a claim with leave to amend, and on October 27, 2025, the Lead Plaintiffs filed their third amended complaint. On December 11, 2025, the Company filed a motion to dismiss Lead Plaintiffs’ third amended complaint, which the Court granted without prejudice on September 30, 2026. On October 21, 2026, the Lead Plaintiffs filed a fourth amended complaint. In light of the fact that the lawsuits are in an early stage, the Company cannot predict the ultimate outcome of the suits. NHS-Galleri Disclosures Federal Securities Class Action And Related Actions On June 5, 2026, a putative securities class action captioned Robbins v. GRAIL, Inc. et al was filed against the Company and certain of its current and former executive officers in the Northern District of California, alleging that defendants violated Sections 10(b) and 20(a) of the Securities Exchange Act and SEC Rule 10b‑5 by making materially false and misleading statements regarding the NHS‑Galleri Trial. The complaint seeks certification of a class of investors who purchased GRAIL stock during the alleged class period and monetary damages, plus interest, attorneys’ and experts’ fees, costs, and other relief that may be awarded by the court. The Company has an indemnification obligation for certain current and former officers involved in the matter pursuant to indemnification agreements entered into by these individuals and GRAIL. The action is at an early stage, and no responsive pleadings have yet been filed. Pursuant to the Private Securities Litigation Reform Act, competing motions for appointment of lead plaintiff and approval of lead counsel were filed by four movants on August 4, 2026. The movants have completed briefing on those motions, but the court has not yet ruled. A hearing on the lead-plaintiff motions is currently scheduled for December 3, 2026. The parties have stipulated to extend defendants’ deadline to respond to the complaint until after the lead plaintiff process is complete, at which point a consolidated amended complaint is expected to be filed. On June 23, 2026, a shareholder derivative action captioned Augitto v. Ragusa et al. was filed against the Company’s current members of our board of directors and certain current and former officers in the Northern District of California, alleging that the defendants breached their fiduciary duties by causing or permitting the Company to make materially false and misleading statements and omissions concerning the NHS‑Galleri Trial, tracking the same alleged misstatements, and omissions underlying the Robbins action. The complaint asserts claims for breach of fiduciary duty, unjust enrichment, abuse of control, gross mismanagement, waste of corporate assets, violations of Exchange Act Section 14(a) in connection with the Company’s 2025 proxy statement, and derivative contribution claims under Sections 10(b) and 21D. The complaint seeks relief on behalf of the Company, including damages, equitable relief, attorneys’ and experts’ fees, costs, and other relief that may be awarded by the court. The action is at an early stage, and no responsive pleadings have yet been filed. On July 16, 2026, the court issued an order relating the action to the Robbins v. GRAIL, Inc. et al. class action. On September 10, 2026, the court entered a stipulated order staying the action pending developments in the related Robbins class action. The matter is currently stayed. In light of the fact that the Robbins and Augitto 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. The Company has entered into indemnification agreements with each of its current and former directors, executive officers, and certain other officers, to provide, among other things, for indemnification to the fullest extent permitted by law and the Company’s certificate of incorporation and bylaws, and has certain obligations 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 Illumina 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 and intellectual property matters. For example, a complaint was filed against the Company on September 11, 2026, alleging the Company’s infringement of two U.S. patents directed to detection of methylation. 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 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, 2026, 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. On June 21, 2024, in connection with the Company’s spin-off from Illumina (the “Spin-Off”), Illumina and the Company entered into the Tax Matters Agreement, dated as of June 21, 2024 (the “Tax Matters Agreement”), which governs the respective rights, responsibilities and obligations of Illumina and the Company after the Spin-Off with respect to all tax matters and includes restrictions to preserve the tax-free status of the Spin-Off during the two-year period following the Spin-Off, which period has expired. The Company remains subject to certain continuing obligations under the Tax Matters Agreement, including an obligation to indemnify Illumina for certain taxes and related losses if the Spin-Off fails to qualify for its intended tax-free treatment as a result of certain actions or events involving the Company’s stock or assets. Breach of any covenant or representation contained in the Tax Matters Agreement will result in liability to specific separation taxes. As of September 30, 2026, as it was not probable that the Company will breach the agreement, no contingent liability was recorded in connection with the Tax Matters Agreement.

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 “Illumina 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 Illumina Actions and to appoint a lead plaintiff (“Lead Plaintiff Motions”). On April 11, 2024, the Court issued an order consolidating the Illumina 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 alleged 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 the U.S. Securities and Exchange Commission (the “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 the Lead Plaintiffs’ second amended complaint for failure to state a claim under Sections 10(b) and 20(a) of the Exchange Act. On September 26, 2025, the court granted the motion to dismiss for failure to state a claim with leave to amend, and on October 27, 2025, the Lead Plaintiffs filed their third amended complaint. On December 11, 2025, the Company filed a motion to dismiss Lead Plaintiffs’ third amended complaint, which the Court granted without prejudice on September 30, 2026. On October 21, 2026, the Lead Plaintiffs filed a fourth amended complaint. In light of the fact that the lawsuits are in an early stage, the Company cannot predict the ultimate outcome of the suits.

On June 5, 2026, a putative securities class action captioned Robbins v. GRAIL, Inc. et al was filed against the Company and certain of its current and former executive officers in the Northern District of California, alleging that defendants violated Sections 10(b) and 20(a) of the Securities Exchange Act and SEC Rule 10b‑5 by making materially false and misleading statements regarding the NHS‑Galleri Trial. The complaint seeks certification of a class of investors who purchased GRAIL stock during the alleged class period and monetary damages, plus interest, attorneys’ and experts’ fees, costs, and other relief that may be awarded by the court. The Company has an indemnification obligation for certain current and former officers involved in the matter pursuant to indemnification agreements entered into by these individuals and GRAIL. The action is at an early stage, and no responsive pleadings have yet been filed. Pursuant to the Private Securities Litigation Reform Act, competing motions for appointment of lead plaintiff and approval of lead counsel were filed by four movants on August 4, 2026. The movants have completed briefing on those motions, but the court has not yet ruled. A hearing on the lead-plaintiff motions is currently scheduled for December 3, 2026. The parties have stipulated to extend defendants’ deadline to respond to the complaint until after the lead plaintiff process is complete, at which point a consolidated amended complaint is expected to be filed.

On June 23, 2026, a shareholder derivative action captioned Augitto v. Ragusa et al. was filed against the Company’s current members of our board of directors and certain current and former officers in the Northern District of California, alleging that the defendants breached their fiduciary duties by causing or permitting the Company to make materially false and misleading statements and omissions concerning the NHS‑Galleri Trial, tracking the same alleged misstatements, and omissions underlying the Robbins action. The complaint asserts claims for breach of fiduciary duty, unjust enrichment, abuse of control, gross mismanagement, waste of corporate assets, violations of Exchange Act Section 14(a) in connection with the Company’s 2025 proxy statement, and derivative contribution claims under Sections 10(b) and 21D. The complaint seeks relief on behalf of the Company, including damages, equitable relief, attorneys’ and experts’ fees, costs, and other relief that may be awarded by the court. The action is at an early stage, and no responsive pleadings have yet been filed. On July 16, 2026, the court issued an order relating the action to the Robbins v. GRAIL, Inc. et al. class action. On September 10, 2026, the court entered a stipulated order staying the action pending developments in the related Robbins class action. The matter is currently stayed.

Legal matters include various claims, complaints, and legal actions that arise from time to time. The Company has entered into indemnification agreements with each of its current and former directors, executive officers, and certain other officers, to provide, among other things, for indemnification to the fullest extent permitted by law and the Company’s certificate of incorporation and bylaws, and has certain obligations 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 Illumina 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 and intellectual property matters. For example, a complaint was filed against the Company on September 11, 2026, alleging the Company’s infringement of two U.S. patents directed to detection of methylation. 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 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, 2026, the Company is unable to estimate a range of possible loss in excess of the amounts accrued.

On June 21, 2024, in connection with the Company’s spin-off from Illumina (the “Spin-Off”), Illumina and the Company entered into the Tax Matters Agreement, dated as of June 21, 2024 (the “Tax Matters Agreement”), which governs the respective rights, responsibilities and obligations of Illumina and the Company after the Spin-Off with respect to all tax matters and includes restrictions to preserve the tax-free status of the Spin-Off during the two-year period following the Spin-Off, which period has expired. The Company remains subject to certain continuing obligations under the Tax Matters Agreement, including an obligation to indemnify Illumina for certain taxes and related losses if the Spin-Off fails to qualify for its intended tax-free treatment as a result of certain actions or events involving the Company’s stock or assets. Breach of any covenant or representation contained in the Tax Matters Agreement will result in liability to specific separation taxes. As of September 30, 2026, as it was not probable that the Company will breach the agreement, no contingent liability was recorded in connection with the Tax Matters Agreement.