The pension plans granted cover substantially all employees. The plans are administered by the Caixa Beneficente dos Empregados da CSN ("CBS"), a private and non-profit pension fund, established in July 1960.

Until December 1995, CBS Previdência managed two defined benefit plans based on years of service, salary, and social security benefits. On December 27, 1995, the Social Security Complementary Secretariat ("SPC") approved the implementation of a new benefit plan, effective from that date, called Mixed Supplementary Benefit Plan ("Mixed Plan"), structured as a variable contribution plan, which has been closed to new enrollments since September 2013. From that date, all new employees must adhere to the CBS Prev Plan, structured in the defined contribution modality, also created in September 2013.

The guarantor resources of CBS are invested mainly in repurchase agreements (backed by federal government securities), federal government securities indexed to inflation, stocks, loans and real estate. As of December 31, 2025, CBS held 6,772,052 common shares of CSN (6,772,052 as of December 31, 2024). The total guaranteed resources of the entity totaled R$6.6 billion as of December 31, 2025 (R$6.5 billion as of December 31, 2024). CBS fund managers seek to combine plan assets with long-term benefit obligations to be paid. The pension funds in Brazil are subject to certain restrictions related to their ability to invest in foreign assets and, consequently, the funds mainly invest in securities in Brazil.

These are considered Guarantor Resources, the available assets and investments of the Benefit Plans, not including the values of contracted debts with sponsors.

For defined benefit plans, called "35% of Salary Average" and "Salary Average Supplementation Plan", the Company maintains a financial guarantee with CBS Previdência, the entity that administers the mentioned plans, with the objective of maintaining financial and actuarial balance in case of any future actuarial loss or actuarial gain.

In accordance with current legislation specific to the pension fund market, for the last 4 fiscal years (2022, 2023, 2024, and 2025), there was no need for CSN to make payments, as the defined benefit plans showed actuarial gains in the fiscal year.

CSN Cimentos Brasil S.A also sponsors the Mauá Prev. This is a variable contribution plan that was offered to employees until the company was acquired by the CSN Group. The following tables summarize the components of net periodic benefit cost recognized in the income statement for Mauá Prev, as well as the capitalization status and amounts that may be recognized in the balance sheet as of December 31, 2025, and 2024.

35% of average salary plan

This plan began to be implemented on February 1, 1966, and is a defined benefit plan, for which the objective is to provide pension payments (length of service, special, disability or age payments) for life. These amounts are equivalent to 35% of the adjusted average of participants’ last 12 monthly salary payments. The plan also guarantees the payment of sickness allowance to the participant licensed by the Official Pension Plan and guarantees the payment of cash, death allowance and pecuniary allowance. This plan was deactivated on October 31, 1977, when the average wage supplementation plan came into force

Average salary supplementation plan

This plan began on November 1, 1977, and is a defined benefit plan. Its objective is to complement the difference between the adjusted average of the participant's last 12 salaries and the Official Social Security benefit for retirement, also on a lifetime basis. As in the 35% plan, there is coverage of sick pay, death and pension benefits. This plan was deactivated on December 26, 1995, with the creation of the mixed supplementary benefit plan.

Mixed Supplemental Benefit Plan

Started on December 27, 1995, it is a variable contribution plan. In addition to the scheduled retirement benefit, risk benefits are provided (active pension, disability, and sick leave/accident aid). In this plan, the retirement benefit is calculated based on what was accumulated through monthly contributions from participants and sponsors, as well as each participant's choice for receiving the benefit, which can be lifelong (with or without continuity of death pension) or based on a percentage applied to the balance of the benefit-generating fund (indefinite term loss). After retirement is granted, the plan has the characteristic of a defined benefit plan, if the participant has chosen to receive their benefit in the form of a lifetime monthly income. This plan was deactivated on September 16, 2013, when the CBSPrev plan went into effect.

CBS Prev Plan

On September 16, 2013, the new CBS Prev pension plan began, which is a defined contribution plan. In this plan, the retirement benefit is determined based on what has been accumulated through monthly contributions from participants and sponsors. Options provided to each participant regarding the form in which amounts are received include: (a) receiving a portion in cash (up to 25%) and the remaining balance through monthly income based on a percentage applied to the benefit-generating fund, which is not applicable to pension benefits due to death, (b) receiving amounts

exclusively as monthly income based on a percentage applied to the benefit-generating fund. With the creation of the CBS Prev plan, the Mixed Supplementary Benefit Plan was deactivated for the entry of new participants starting September 16, 2013.

Mauá Prev Plan

The Mauá Prev plan is offered by CSN Cimentos Brasil S.A. (previously named LafargeHolcim Brasil S.A.) acquired in 2022 and sponsors the Mauá Prev Retirement Plan to its employees. This is the plan that the company made available to all its employees in Brazil as of December 1, 2016. Until 2009, its predecessor, Lafarge Brasil S/A, sponsored two plans, a defined contribution plan and a defined benefit plan. On July 1, 2009, the plans were merged, resulting in only one variable contribution plan, safeguarding the acquired rights of those who had already completed the eligibility requirements of the defined benefit rules. Furthermore, the Company has registered in a collective agreement part of its plant’s commitments related to the bonus, due when the dismissal of the retired employee by Social Security. The following tables present the commitments related to this bonus, as well as the capitalization status and the amounts that can be recognized in the balance sheet.

ACT Plan

CSN Cimentos Brasil (CIBR) has post-employment benefits linked to Collective Bargaining Agreements (ACT), which provides for the payment of multiple salaries, as well as compensation from the FGTS (Guarantee Fund for Length of Service) if the employee leaves the company due to retirement.

The investment policy establishes principles and guidelines governing the investment of resources entrusted to the entity, aiming to promote the necessary security, liquidity, and profitability to ensure balance between plan assets and liabilities. This policy is based on the Asset Liability Management (ALM) study, which considers the benefits of participants and beneficiaries of each plan.

The investment plan is reviewed annually and approved by the Steering Council while considering a five-year horizon, as established by the Resolution from the Complementary Pension Management Council - CGPC No. 7, of December 2003. The investment limits and criteria established in the policy are based on Resolution No. 4.661/18, published by the National Monetary Council - CMN.

The actuarial calculations are updated at the end of each fiscal year by external actuaries and presented in the financial statements in accordance with IAS 19 - Employee Benefits.

The reconciliation of assets and liabilities of employee benefits and the ACT is presented below:

The change in the present value of the defined benefit obligation is shown below:

Changes in the fair value of assets under the defined benefit plan are shown below:

The composition of the amounts under established benefit plans and ACT area recognized in the income statement is shown below:

The (cost)/income is recognized in the income statement in other operating expenses.

The changes in actuarial gains and losses of defined benefit plans are shown below:

The breakdown of actuarial gains and losses is shown below:

The main actuarial assumptions used were as follows:

The assumptions regarding the mortality table are based on published statistics and mortality tables. These tables translate into an average life expectancy in years of employees aged 65 years and 40 years:

Allocation of defined benefit assets:

Assets invested in variable income are mainly invested in CSN shares.

Fixed income assets are mainly composed of debentures and National Treasury Notes (“NTN-B”).

Real estate refers to buildings valued by a specialized asset valuation company. There are no assets in use by CSN and its subsidiaries.

For the mixed supplementary benefit plan, the expense in 2025 was R$1,178 (R$ 314 on December 31, 2024).

The supplementary mixed benefit plan, the expected contributions to the defined contribution tranche totaled R$20,175 and R$1,096 for the defined benefit tranche (risk benefits), respectivel y, in 2026.

The quantitative sensitivity analysis regarding the significant assumptions, for the pension plans as of December 31, 2024, is shown below:

Following are the expected benefits for future years for defined benefit plans:

It refers to the health plan created on December 1, 1996, exclusively to cover former retired employees, pensioners, amnesties, ex-combatants, widows of labor accident victims and retirees until March 20, 1997 and their respective legal dependents. Since then, the health plan has not allowed the inclusion of new beneficiaries. The Plan is sponsored by CSN.  

The amounts recognized in the balance sheet were as follows:

The reconciliation of health benefit liabilities is as follows:

The actuarial gains and losses recognized in equity are as follows:

The following is the weighted average life expectancy based on the mortality table used to determine actuarial obligations:

Below is the weighted average life expectancy based on the mortality table used to determine actuarial obligations:

The quantitative sensitivity analysis for significant assumptions for the post-employment health plans as of December 31, 2025, is as follows:

Following are the expected benefits for future years of the post-employment health plans:

Accounting Policy

Long-term employee benefits

A defined contribution plan is a post-employment benefit plan in which the Company pays contributions to CBS. Obligations for contributions to defined contribution pension plans are recognized as employee benefit expenses in the income statement during the periods in which services are provided by employees. In this modality, the Company will have no legal or constructive obligation to pay additional amounts, as the risks fall on the employees.

For the defined benefit plan, the obligations are valued annually by independent actuaries using the unit credit method, with assumptions including biometric, demographic, financial and economic hypotheses. The discount rate is applied to set the present value of benefit obligations defined, the fair value of the assets is also determined. The amount recognized in the Company's balance sheet is the net of obligations after the discount rate less the fair value of assets.

When the calculation results in a benefit for the Company, the asset to be recognized is limited to the total of any unrecognized past service costs and the present value of economic benefits available in the form of future plan refunds or reduction in future plan contributions. Actuarial gains and losses resulting from defined benefit plans immediately in other comprehensive income. In the event of termination of the plan, the accumulated actuarial gains and losses are recorded in the income statement.

Short-term employee benefits

Payments of benefits such as salary or vacation, as well as the respective labor charges levied on these benefits are recognized monthly in the income statement, respecting the accrual basis.

Employee profit sharing and executive variable compensation are linked to the achievement of operational and financial targets. The Company recognizes a liability and an expense substantially when these targets are achieved, allocating them to the production cost or operational expenses.