NewAmsterdam Pharma Co N.V. Income Taxes Disclosure

Note 12. Income Taxes

Deferred income taxes reflect the tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of our deferred tax assets are as follows as of December 31, 2025 and 2024:

Realization of deferred tax assets is dependent on future taxable income, if any, the timing and the amount of which are uncertain. We assess the available positive and negative evidence to estimate whether sufficient future taxable income will be generated to permit use of the existing deferred tax assets. A significant component of objective negative evidence evaluated was our cumulative loss incurred over the three-year period ended December 31, 2025. Such objective evidence limits the ability to consider other subjective evidence, such as our projections for future growth. On the basis of this evaluation, as at December 31, 2025, December 31, 2024 and December 31, 2023, a full valuation allowance has been recorded against our net deferred tax asset. As of December 31, 2025, and December 31, 2024, the Company had a valuation allowance of $217.0 million and $184.6 million, respectively, recorded on the balance sheet. A valuation allowance is a non-cash charge, and does not limit the Company’s ability to utilize its deferred tax assets, including its ability to utilize tax loss and credit carryforward amounts, against future taxable income. The amount of the deferred tax asset considered realizable, however, could be adjusted if estimates of future taxable income during the carryforward period are reduced or increased or if objective negative evidence in the form

of cumulative losses is no longer present and additional weight is given to subjective evidence such as our projections for growth.

As of December 31, 2025, we had net operating loss carryforwards for Netherlands fiscal unity, US, and state income tax purposes of $362.5 million, $153.1 million, and $72.8 million, respectively. These balances have been updated to reflect ongoing discussions with the Dutch Tax Authorities. It is currently expected that the outcome of these discussions will result in an amortizable IP asset in exchange for the carry-forward losses through April 8, 2020. A deferred tax asset has been recorded accordingly.

We also have federal research and development tax credit carryforwards of approximately $4.2 million that expire beginning in 2043 and state research and development tax credit carryforwards of approximately $1.8 million which can be carried forward indefinitely.

The future utilization of net operating loss and tax credit carryforwards and credits may be subject to an annual limitation, due to Dutch and US tax law and as a result of ownership changes that may have occurred previously or that could occur in the future. Due to the existence of the valuation allowance, limitations will not impact our effective tax rate.

We recognize a tax benefit from an uncertain tax position when it is more likely than not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, based on the technical merits. Income tax positions must meet a more likely than not recognition at the effective date to be recognized. As of December 31, 2025 we have not identified any unrecognized tax benefits that should be recorded.

We have elected to include interest and penalties as a component of tax expense. During the years ended December 31, 2025, 2024 and 2023, we did not recognize accrued interest and penalties related to unrecognized tax benefits. Although the timing and outcome of an income tax audit is highly uncertain, we do not anticipate that the amount of existing unrecognized tax benefits will significantly change during the next 12 months.

With an effective date of November 21, 2022, NewAmsterdam Pharma Company N.V. formed a fiscal unity with NewAmsterdam Pharma Holding B.V. and NewAmsterdam Pharma B.V. for corporate income tax purposes. A company and its subsidiaries that are part of the fiscal unity are jointly and severally liable for the tax payable by the fiscal unity.

We are subject to taxation in the United States, the Netherlands and various state jurisdictions. As of December 31, 2025, the tax years for 2022, 2023 and 2024 are subject to examination by the tax authorities in the United States and the tax years for 2023 and 2024 are subject to examination by the tax authorities in the Netherlands. Due to our net operating loss and tax credit carryforwards, the income tax returns remain open to U.S. federal and state tax examinations. The Company is not currently under examination in any tax jurisdiction.