Japan's Premium Adjustment Program for Part-Time Workers

This is an English translation of our Japanese article. Rules and figures may change; the Japanese version and official sources are authoritative.

Last updated: September 7, 2026 / This article is based on the Japan Pension Service's "Notice on the premium adjustment program" and the Ministry of Health, Labour and Welfare's published materials on the expansion of social-insurance coverage (as of September 7, 2026). Some administrative details, such as the burden ratios by remuneration bracket, will be finalized in future guidance from the Pension Service. Always confirm whether you are covered with your workplace or a pension office.

On October 1, 2026, the "¥1.06 million wall" for part-time and arbeit workers will be abolished, and the number of people newly starting to pay social-insurance premiums will grow sharply. In its shadow, quietly starting on the very same day, is the premium adjustment program — a program under which your company bears part of the premiums you would otherwise pay. The extra amount the company pays comes back to it in full from the state later, so the company's wallet doesn't hurt either. And yet the program is almost completely unknown. The ones newly bearing premiums are the workers themselves, but publicity for the mechanism that softens that burden has not kept up. Right now only those who know about it benefit, so this article organizes everything — who is covered, the amounts, and how to raise it with your company.

Key points of this article

① The program covers short-time workers with a standard monthly remuneration of ¥126,000 or less who newly join social insurance at a workplace with 50 or fewer employees (an establishment that applies social insurance by labor-management agreement on or after October 1, 2026).
② For a total of 3 years from enrollment, the company can additionally bear part of the premiums the worker pays. In some examples, the worker's share in years 1–2 is half the normal amount (it depends on the bracket).
③ The company's additional burden is deducted in full from the premiums it pays later — the company's final burden does not increase.
④ Even with reduced premiums, your future pension is calculated at the full amount (it is not cut).
⑤ To use it, a request from the company is required. It is not applied automatically, so if you seem to qualify, check with your company.

Social insurance

What the program is — tilting the "50-50 split" toward the company for a limited time

Social-insurance premiums (health insurance and employees' pension) are, as a rule, split half-and-half between the company and the worker. The premium adjustment program creates a time-limited exception to this fifty-fifty principle, allowing the company to shoulder part of the worker's share as well[Japan Pension Service leaflet (PDF, in Japanese)].

The burden ratio differs by wage bracket, but in the lowest bracket, for example, the picture looks like this (an example shown in commentary for tax professionals and the like; check the Pension Service's guidance for the official bracket-by-bracket ratios).

Period	Worker : company burden ratio (example)	How it feels for the worker
Years 1–2	25 : 75	Half the normal burden
Year 3	37.5 : 62.5	Three-quarters of normal
Year 4 onward	50 : 50	Normal (program ends)

How the worker : company premium split shifts (lowest-bracket example). In years 1–2, the worker's share is half the normal burden

Let's also picture the amounts. With a standard monthly remuneration of ¥88,000 (a monthly salary in the high ¥80,000 range), the worker's share of health-insurance plus employees'-pension premiums is roughly ¥12,000–13,000 a month (an approximation under Kyokai Kenpo; rates differ by prefecture). In an example where the worker's share is halved, the company shoulders about ¥6,000 a month, about ¥70,000 a year. Imagine the take-home-pay "cliff" becoming exactly half as tall, and you can see the size of the impact.

What matters just as much: your future pension is not reduced even though your premiums are lightened. The pension is calculated on the original standard monthly remuneration, so you enroll cheaply and receive the full amount — for those who qualify, a straightforwardly good deal[Japan Pension Service (in Japanese)].

Eligibility is narrow — first check whether you are covered

To be honest, the scope of this program is quite narrow. You must meet all three of the following.

Your workplace has 50 or fewer employees and becomes an establishment that applies social insurance based on labor-management agreement on or after October 1, 2026 (a voluntarily specified establishment). Companies that were already voluntarily covered on or before September 30, 2026 are not eligible.
You are a short-time worker who newly joins social insurance (health insurance and employees' pension) at that workplace. Those already enrolled are not eligible.
Your standard monthly remuneration is ¥126,000 or less (roughly a monthly salary up to around ¥130,000).

A common misunderstanding: those joining from October at a company with 51 or more employees are not covered

The people who newly join social insurance under the October 1, 2026 abolition of the "¥1.06 million wall" are mainly those working 20 hours or more a week at companies with 51 or more employees. But the premium adjustment program covers companies with 50 or fewer. In other words, most of the people compulsorily enrolled by the wall's abolition cannot receive this relief. On the same October 1, two systems start side by side — "enrollment is mandatory, relief is a narrow gate" — and from the standpoint of those newly paying, the mismatch is hard to deny. All the more reason for those who do fall within the scope to use it to the full. The abolition of the wall itself is explained in the ¥1.06M and ¥1.30M walls and the minimum wage and ¥1.06M wall double reform.

The company doesn't lose — so asking costs nothing

You may feel that "asking the company to take on an extra burden is awkward." Here is the interesting part of the program's design: the amount the company additionally bears is later deducted in full from the premiums the company pays. It is a temporary advance, and the company's final burden does not increase by a single yen[Japan Pension Service (in Japanese)].

Merits for the company: with zero net burden, it can say "here, the drop in your take-home pay is halved," which makes the program a weapon for recruiting and retaining part-time workers. For small companies short of staff, it is hard to find a reason not to use it.
Tax treatment: the premiums the company additionally bears are treated as not constituting the employee's salary, and no income-tax withholding is required (the workplace's accounting staff or tax adviser should confirm the treatment to be safe).
Procedure: the company must file a request with the pension office and the like within 2 years from the day the person became covered. It is not applied automatically.

Seen from the worker's side, asking your company costs zero, and success is worth tens of thousands of yen a year. This is not a moment for holding back.

Steps until you use it (for workers)

Check your workplace's size: whether the number of employees (persons insured under the employees' pension) is 50 or fewer. If it is 51 or more, unfortunately this program does not apply (for the enrollment rules, see the walls article).
Ask whether the company plans to apply social insurance: coverage at companies with 50 or fewer employees depends on labor-management agreement. The quickest route is to name the program: "Do you plan to make it possible for us to join social insurance from October? Will you use the premium adjustment program then?"
Estimate the change in your take-home pay: you can check your take-home pay after joining with the dependent-wall simulator. The smartest use of the program is to plan, within the 3 years of relief, to increase your work up to the reversal line of about ¥1.5–1.6 million a year.

FAQ

I will join social insurance from October at a company with 51 or more employees. Am I covered?

No. The premium adjustment program is limited to workplaces with 50 or fewer employees that apply social insurance by labor-management agreement on or after October 1, 2026 (voluntarily specified establishments). If you join at a company with 51 or more employees due to the abolition of the ¥1.06 million wall, you may instead be covered by the "income wall" support-strengthening package (such as the social-insurance application promotion allowance), so check with your workplace.

Summary

The premium adjustment system starts October 1, 2026. Employers can voluntarily cover part of an employee's share of social insurance premiums, and in some cases the employee's burden in years 1-2 becomes half of the usual amount.
It applies to short-time workers with a standard monthly remuneration of ¥126,000 or less who newly join social insurance at a workplace with 50 or fewer employees that opts in by labor-management agreement on or after October 1, 2026.
People who join social insurance because their employer has 51 or more employees, under the removal of the ¥1.06 million threshold, are not eligible.
The employer's extra contribution is fully deducted from premiums paid later. The employer's total cost does not increase, and the pension amount is still calculated at the full rate.
The system is not applied automatically; the employer must opt in. Confirm your workplace's size and ask about it by name.

Reference links (sources)

* Administrative details such as the bracket-by-bracket burden ratios and filing forms will be finalized in future guidance from the Japan Pension Service. This article is general information; for individual decisions, please confirm with your workplace, a pension office, or a licensed social-insurance consultant.