Japan operates a well-structured but multilayered public pension system that applies to residents in Japan aged 20 to under 60 – including foreign nationals. With mandatory enrolment, shared contributions, and a growing range of voluntary corporate pension options, employers operating in Japan need to understand both their legal obligations and the strategic choices available to them. 

Japan’s public pension system is built on a two-tier structure. The first tier is the National Pension (‘kokumin nenkin’), which covers all residents aged 20 to under 60. The second tier is the Employees’ Pension Insurance (‘kosei nenkin hoken’), which generally applies to private-sector employees and certain public-sector workers. 

The two tiers operate together rather than as alternatives. Employees covered by the Employees’ Pension Insurance are automatically enrolled in the National Pension at the same time, as Category II insured persons, meaning that most employees in Japan participate in both schemes simultaneously from the start of their employment. 

The system is designed to provide financial protection in the event of old age, disability or death. Premiums for the Employees’ Pension Insurance are calculated as a percentage of salary and split equally between the employer and employee. In practice, the employer deducts the employee’s share from salary and remits both shares to the pension authorities. 

To qualify for an old-age basic pension, employees must accumulate a minimum qualification period of 10 years, covering both paid and exempted periods. For foreign nationals on shorter postings who are unlikely to reach this threshold, a Lump-sum Withdrawal Payment (‘dattai ichijikin’) may be available as a partial refund of contributions after leaving Japan. Where Japan has a bilateral social security agreement with the employee’s home country, the treatment of pension coverage periods should be reviewed before any application for a withdrawal payment is made. 

Under Japanese law, employers are not required to provide employees with access to any supplementary pension arrangement beyond the statutory public schemes. However, employers may voluntarily establish, fund and operate their own corporate pension plan. 

Corporate pension plans in Japan broadly take two forms. Under a defined benefit (DB) plan, the employer funds a benefit formula under which the amount payable at retirement is determined in advance by the plan rules. Under a defined contribution (DC) plan, the employer pays contributions into individual employee accounts, and the eventual benefit depends on the amount contributed and the investment returns generated over time. In addition to DB and DC plans, further common arrangements include contract-type and fund-type corporate pension plans. 

Employers looking to amend an existing corporate pension plan – particularly where proposed changes would reduce or otherwise disadvantage employees – must navigate a carefully regulated process under Japanese law. 

The precise requirements depend on the type of plan involved. Broadly speaking, a disadvantageous change may require the consent of plan participants, beneficiaries or labour unions, as well as formal explanations to participants and filings with the relevant authorities. Where a corporate pension forms part of the employer’s work rules – as is typically the case with contract-type plans – any adverse amendment is also subject to the reasonableness test under the Labour Contract Act. The reasonableness test is applied strictly, taking into account factors including the necessity and reasonableness of the change, the degree of disadvantage suffered by employees, and the status of negotiations with the labour union. Because the reasonableness test is applied strictly in practice, it is generally advisable to obtain employees’ consent whenever possible. Where the arrangement is governed by a collective bargaining agreement, union agreement will generally be required before any change can take effect. 

Japan’s pension tax framework operates on a broadly tax-deferred basis. Contributions to both public and corporate pension schemes are tax-advantaged, and investment returns within DC plans accumulate on a tax-free or tax-deferred basis. Benefits are taxed when they are paid out, but relief is available. For employees who take their pension as a lump sum, a retirement income deduction applies and only half of what remains is subject to tax. Those who receive their pension as regular payments are taxed on those payments as miscellaneous income. 

Because statutory pension enrolment is automatic under Japanese law, employment contracts do not need to spell out the detail of the public pension entitlement. In practice, however, most contracts confirm whether the employee will be enrolled in Employees’ Pension Insurance, as this is an important term of employment. 

Where the employer runs a corporate pension plan, the contract or work rules should mention that it exists, with the full terms set out separately in the plan documents. Where no corporate plan is offered, it is best practice to set this out clearly in the contract. 

• Enrolment in the public pension system is mandatory. Residents in Japan aged 20 to under 60, including foreign nationals, must be enrolled in the National Pension and, where applicable, the Employees’ Pension Insurance, from the start of their employment. 

• Employer contributions to the Employees’ Pension Insurance are split equally with employees. The employer deducts the employee’s share from salary and remits both shares to the authorities. 

• There is no obligation to offer a supplementary corporate pension, but employers may voluntarily establish, fund and operate their own plan if they wish to do so. 

• Any reduction in existing pension benefits should be managed with care. Employee consent, union engagement and regulatory filings may all be required, and it is generally advisable to obtain employee consent even where it is not strictly required. 

• Foreign nationals should be advised about the 10-year qualification period, the availability of the Lump-sum Withdrawal Payment, and the potential relevance of any bilateral social security agreement with their home country. 

• Document pension arrangements clearly in employment contracts and work rules, referring to the applicable plan documents for the detail.