National Health Insurance plan 国民健康保険

National Health insurance plan

"National health insurance plan" covers self-employed workers and non-employed people at the age under 75. In other words, the plan covers people who don't join the Social health insurance plan. The Social health insurance plan is regarded relatively more favorable to the insureds than the National health insurance plan, although there are not so decisive differences between these 2 insurance plans as long as the insureds are under usual conditions. But only designated people can be accepted into the Social health insurance plan and others have to join the National health insurance plan.

Foreign nationals at the age under 75, who are not covered by another public health insurance plan, are also supposed to join the National health insurance plan, in case they are registered in the Residence registry or otherwise they live the city. Here, the "live" means stay in the municipality for 3 month or longer.

[In Japanese]


Enrollment Procedures

The enrollment procedures for the National health Insurance plan shall be conducted by the insureds themselves. The procedures are dealt at the municipal office. When people become the insureds of the plan, they are supposed to immediately go to the municipal office and submit appropriate reports, which certificate the reason why they are entered in the plan. In case you enter the National health insurance plan after retirement from a company joining the Social health insurance plan, you shall submit the certificate of loss of the qualification issued from the insurer of the Social health insurance plan.

[In Japanese]

Insurance premiums

The National Health Insurance premiums are determined and notified to you in every June, by the local government. The calculation methods are various by municipalities. The calculation elements are not absolutely uniformed, but usually a per-income basis, a per-capita basis and a per-property basis are adopted.

The premiums are calculated and levied on each household. It is important when we consider the maximum limitation amount. If the income amount of a member of a household is quite large, the premium amount on the household easily reaches the limitation. In this case, even if there are many other insureds with high earnings, no additional premiums are levied.

As to the premiums amount, I have to point out that the collection ratio of the premiums is very low. I think one of the main reasons is that the premiums amount quite often go too high for poor people. They implement different preferential treatments for those who cannot make money for it. But many of them requires appropriate application from the qualified insureds and the submission of the application is not easy for the poor insureds.

[In Japanese]
国民健康保険の保険料は世帯単位で計算され、賦課されます。これは最大限度額を考慮するときに重要な意味をもってきます。 家族のうち1人の所得が多額であったときには、保険料はすぐに最大限度額に達してしまいます。その場合、その世帯内に多額の所得を持つ人が大勢居たとしても、それ以上の保険料かかりません。


payment method

You shall pay the premiums in 10 installments at the each month's end from June to the next March. You can pay it at once or in 2 installments by your choice. I recommend applying for the automatic transfer from your bank account. It prevents you from omitting the payments and saves you the trouble of going to a bank and waiting for your turn.

[In Japanese]
国民健康保険料は、6月から翌年3月までの各月末に10回に分けて納付します。その選択により、1回あるいは2回の分割払いとすることも可能です。 納付漏れを防ぐことや、銀行に行って順番待ちをするといった手間を省くことができることから、自動振替の申し込みをしておくことをお勧めします。

Actual case of the premium calculation

I introduce 2 actual cases of the premium calculation. One is that in Gotsu city, Shimane prefecture. The other is that in Kita ward, Tokyo.

On the insureds at the age from 40 through 65, premiums for the Nursing care Insurance system are levied together. These charts show the total of the premium rates for these 2 public insurance systems for people at the age range.

National health insurance premiums in Gotsu city for 2023

Element Premium amount/rate(1) Premium amount/rate(2)
Income ※1 11.6% 14.3%
Per capita ※2 31,300yen/each 39,900yen/each
Per household 20,500yen 24,700yen
Maximum Limitation 870,000yen 1,040,000yen

National health insurance premiums in Kita ward, Tokyo for 2024

Element Premium amount/rate (1) Premium amount/rate (2)
Income ※1 11.49% 13.77%
Per capita ※2 65,600yen/each 82,100yen/each
Maximum Limitation 890,000yen 1,060,000yen

※1 The calculation basis is the total sum of the income amount (after 430,000yen deduction for each insured), gained by the insureds in the household for the previous years.
※2 The calculation basis is the number of the insureds in the household.
(1) For the insureds at the age under 40 or over 65.
(2) For the insureds at the age from 40 through 65

You can find the maximum limitation of the premium amount is common between these 2 municipalities. But the calculation methods are not uniformed. Actually, the premium amount level is surprisingly different.

Given you, 45years old, live alone and your relevant income is 5 million yen, the premium amount shall be 779,600yen in Gotsu city, but 770,600yen in Kita ward. When the benefits are common, how can this gap be justified?

[In Japanese]


島根県江津市の国民健康保険料 2023年

算定要素 保険料率/額(1) 保険料率/額(2)
所得割 11.6% 14.3%
均等割 31,300円/人 39,900円/人
世帯割 20,500円 24,700円
最大限度額 870,000円 1,040,000円

東京都北区の国民健康保険料 2024年

算定要素 保険料率/額(1) 保険料率/額(2)
所得割 11.49% 13.77%
均等割 65,600円/人 82,100円/人
最大限度額 890,000円 1,060,000円

※1 世帯内の被保険者の前年分課税所得(43万円控除後)の合計額
※2 世帯内の被保険者の人数
(1) 40歳未満または65歳超の被保険者の場合
(2) 40歳以上65歳以下の被保険者の場合


もし、45歳で所得5百万円の単身者世帯であるとすると、江津市に住んでいれば779,600円、東京都北区に住んでいれば770,600円の国民健康保険料額となります。 給付サービスが同等のものであるのに、このような大きな格差はどのように正当化されるのでしょうか?