When working part-time or as a temporary employee, enrollment in “Employment Insurance,” “Health Insurance,” and “Employee Pension Insurance” is mandatory if certain conditions are met.
These are important systems designed to protect workers’ livelihoods, but the eligibility criteria are strictly defined based on working hours and wages.
- Eligibility Requirements and Benefits of Employment Insurance
- Eligibility Criteria for Health Insurance and Employees’ Pension Insurance
- Benefits and Contribution Structure of Social Insurance Enrollment
- Standard Monthly Earnings Used to Determine Premiums
- Summary of Key Points on Social Insurance Coverage Rules
Eligibility Requirements and Benefits of Employment Insurance
Employment Insurance is a system primarily designed to provide financial security during unemployment and support for re-employment.
To be eligible, you must meet all three requirements, specifically: “working at least 20 hours per week” and “expected to be employed for at least 31 days.”
Note that full-time daytime students (excluding those in correspondence or part-time programs) are generally not eligible.
If you leave your job after being enrolled for at least one year, you are eligible to receive basic benefits (unemployment benefits) as well as a wide range of other support, such as educational and training benefits and childcare leave benefits.
Unlike workers’ compensation insurance, insurance premiums are shared between the employer and the employee.
Eligibility Criteria for Health Insurance and Employees’ Pension Insurance
Health Insurance and Employees’ Pension Insurance generally apply to employees who work at least three-quarters of the “scheduled weekly working hours” and “scheduled monthly working days” of a full-time employee.
However, even if these criteria are not met, employees may still be eligible for enrollment as “specified part-time workers” if they work for a company with 51 or more employees (effective October 2024).
In such cases, the conditions are: a scheduled weekly working hours of 20 hours or more, a monthly wage of 88,000 yen or more, an expected employment period of more than two months, and the employee must not be a student.
Benefits and Contribution Structure of Social Insurance Enrollment
Upon enrolling in social insurance, Health Insurance provides not only medical benefits for illness or injury but also “sickness allowance” during leave and “maternity allowance” upon childbirth.
In addition, under the Employees’ Pension Insurance system, the “Old-Age Employees’ Pension” is added to the future Basic Old-Age Pension, and comprehensive coverage is provided through disability and survivors’ pensions.
Premiums are generally split equally between the employer and the employee, and the Employees’ Pension Insurance premium rate is a fixed rate of 18.3%.
If you are not covered by social insurance and are not a dependent of a family member, you must enroll in the National Health Insurance and National Pension systems on your own.
According to data, the monthly National Pension premium for 2026 (FY 2026) is set at 17,060 yen.
Standard Monthly Earnings Used to Determine Premiums
The actual premiums you pay and the benefits you receive are determined based on your “standard monthly earnings.”
This amount is adjusted to reflect actual circumstances through the “qualification acquisition” (determined based on the terms of the employment contract at the time of hiring), the “regular determination” (revised annually based on earnings from April to June), and the “ad hoc revision” (applied when there are significant changes, such as a pay raise).
Based on the information provided, we have concisely summarized the key points regarding social insurance coverage for part-time and temporary workers.
Summary of Key Points on Social Insurance Coverage Rules
- Eligibility Requirements for Employment Insurance
Coverage applies if all three of the following conditions are met: working 20 or more hours per week, an expected employment period of 31 days or more, and being a non-student (excluding correspondence and part-time students). - Basic Rules for Health Insurance and Employees’ Pension Insurance
Eligibility applies if an employee works at least three-quarters of the weekly working hours and monthly working days of a regular employee. - Expanded Coverage for Specific Part-Time Workers
In companies with 51 or more employees, enrollment is required if the worker meets the following conditions: working 20 or more hours per week, earning a monthly wage of 88,000 yen or more, expected to be employed for more than two months, and not a student. - Benefits and Costs of Social Insurance Enrollment
Premiums are split equally between the employee and the employer (the Employee Pension Insurance rate is a fixed 18.3%), and you are eligible for generous benefits, such as sickness allowance and a supplement to your future old-age Employee Pension. - Comparison with the National Pension
If you are not enrolled in social insurance and are not a dependent, you must pay for the National Pension (17,060 yen per month in fiscal year 2026) and National Health Insurance on your own. - How Premiums Are Calculated
Premiums are based on the “standard monthly remuneration.” The amount is determined at the time of hire, through an annual review, and through ad hoc adjustments following significant pay raises.
