About National Health Insurance Tax

Calculation Method of National Health Insurance Tax

The tax year for the National Health Insurance Tax is from April to March of the following year. It is calculated by summing the "Basic Tax Amount (Medical Portion)", "Late-Stage Elderly Support Fund Tax Amount (Support Portion)", and "Child and Parenting Support Contribution Tax Amount (Child Portion)" applicable to all National Health Insurance subscribers, along with the "Nursing Care Contribution Tax Amount (Nursing Care Portion)" applicable to those aged 40 and over but under 65.

FY2026 National Health Insurance Tax = Medical Portion (Income-based + Per Capita) + Support Portion (Income-based + Per Capita) + Child Portion (Income-based + Per Capita + Per Capita for those 18 and older) + Long-Term Care Portion (Income-based + Per Capita)

Basic Tax Amount (Medical Portion)

Of the Medical Expenses for National Health Insurance subscribers, the amount allocated (the insurance benefit amount borne by Inagi City) excludes the out-of-pocket expenses paid at medical institutions.

Late-Stage Elderly Medical Care Subsidy Tax Amount (Subsidy Portion)

This will be used for subsidies for the Late-Stage Elderly Medical Care system for those aged 75 and older.

Child Care Support Contribution Tax Amount (Children's Portion)

This will be used for the Child Care Support Contribution to address the declining birthrate.

For insured persons under 18 years old, the per capita levy is fully reduced.

For insured persons 18 years and older, the income-based levy, per capita levy, and per capita levy for those 18 and older are imposed.

• About the Child and Parenting Support Fund System (Children and Families Agency Website)(External Link)

Tax Amount for Long-Term Care Contributions (Long-Term Care Portion)

Contributions to Long-Term Care Insurance will be allocated for those aged 40 to under 65 (2nd category insured persons under Long-Term Care Insurance).

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FY2026 National Health Insurance Tax Rates

Item	Medical Portion	Support Fund Portion	Child Portion	Care Portion	Subtotal
Income-based Portion: (Total Income Amount, etc. – Basic Deduction of 430,000 yen) ×	5.65%	2.21%	0.3%	2.19%	10.35%
Per capita rate: Number of subscribers ×	36,800 yen	14,400 yen	1,820 yen	13,100 yen	66,120 yen
Equal Rate for 18 and Older: Number of Subscribers 18 and Older ×			110 yen		110 yen
Taxation Limit Amount	670,000 yen	260,000 yen	30,000 yen	170,000 yen	1,130,000 yen

Notice

• The total income amount used for calculating the income tax refers to the total income amount in 2025 plus income from forestry and income subject to separate taxation, among others. For example, in the case of salary income only, the "Amount after salary income deduction" on the withholding slip is considered salary income, which becomes the total income amount.
• When calculating the income tax, a basic deduction of 430,000 yen is applied for each person with income. If the total income amount is 430,000 yen or less, the total income amount used for the income tax calculation is considered to be 0 yen. Additionally, if the total income amount exceeds 24 million yen, the basic deduction amount is reduced.
• The income-based portion applies to the income of all members enrolled in the National Health Insurance.
• There are no income deductions (such as Medical Expenses deductions) or tax credits (such as dividend credits) like Income Tax or resident tax.

[Question] For example, how much will the National Health Insurance Tax be for the following household?

Relationship	Age	Income
Household Head (Self-Employed)	50 years old	3 million yen
Wife (Part-time)	45 years old	1.5 million yen
Child (Student)	22 years old	None

[Answer] The National Health Insurance Tax is as follows.

Category	Medical Portion (All Subscribers)	Support Fund Portion (All Subscribers)	Child Portion (For those aged 18 and above)	Care Portion (For those aged 40 and above but under 65)
Income Tax	{(3,000,000 yen - 430,000 yen) + (1,500,000 yen - 430,000 yen) ×5.65% = 205,660 yen	{(3,000,000 yen - 430,000 yen) + (1,500,000 yen - 430,000 yen) ×2.21% = 80,444 yen	{(3,000,000 yen - 430,000 yen) + (1,500,000 yen - 430,000 yen) ×0.3% = 10,920 yen	{(3,000,000 yen - 430,000 yen) + (1,500,000 yen - 430,000 yen) ×2.19% = 79,716 yen
Equal Division	3 people × 36,800 yen = 110,400 yen	3 people × 14,400 yen = 43,200 yen	3 people × 1,820 yen = 5,460 yen	2 people × 13,100 yen = 26,200 yen
Equal share for those 18 and older			3 people × 110 yen = 330 yen
Subtotal	316,000 yen	123,600 yen	16,700 yen	105,900 yen

Note: Subtotal amounts are rounded down to the nearest 100 yen for each of the medical, support fund, child, and long-term care portions.
As a result of the calculation, medical portion 316,000 yen + support fund portion 123,600 yen + child portion 16,700 yen + long-term care portion 105,900 yen = 562,200 yen will be the National Health Insurance Tax for one year.

Please note that the above calculation process has been simplified for explanation purposes. Due to rounding and various factors, the actual payment amount may differ, so please understand.

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The taxpayer is the head of the household (Tax is levied on the head of the household for all members of the household who are enrolled in the National Health Insurance).

Even if the head of the household is enrolled in social insurance, if household members are enrolled in National Health Insurance, the taxpayer will be the head of the household (Local Tax Act Article 703-4, Inagi City National Health Insurance Tax Ordinance Article 1). In this case, the head of the household is called the "deemed head of household," and the entire household is called the "deemed household." Please note that when calculating the National Health Insurance Tax, the income-based portion, per capita portion, and per capita portion for those aged 18 and over related to the deemed head of household are not included.

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The monthly tax will be prorated according to the number of months of enrollment.

When calculating the National Health Insurance Tax, it is calculated according to the number of months of enrollment. The period subject to taxation is from the month you joined the National Health Insurance to the month before the month you withdraw (if you withdraw in the same month you joined, that month is not taxed).
If there is a change in enrollment or withdrawal during the fiscal year, or a change in the head of the household, the tax amount will be adjusted each time, and a notice of tax amount change will be sent.
For those who turn 75 during the fiscal year, the calculation is made up to the month before transitioning to the Late-Stage Elderly Medical Care system.

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When does the membership start?

Joining the National Health Insurance is effective from the date you actually meet the eligibility requirements, such as the date you moved to Inagi City or the date you canceled another health insurance, rather than the date you completed the enrollment procedure. The National Health Insurance Tax will also be retroactively applied from the point you meet the eligibility requirements. Please submit your Notification within 14 days.

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If you join another health insurance

When your health insurance changes, such as joining social insurance or a National Health Insurance union, you must submit a Notification to withdraw from the National Health Insurance. If you do not complete this procedure, you will be charged both the National Health Insurance Tax and the health insurance premiums from your company or other sources. Please bring your My Number Health Insurance Card, qualification confirmation documents for social insurance and National Health Insurance, and qualification information notices, and complete the procedure within 14 days.

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Even those without income should file a declaration

Accurate calculation of the National Health Insurance Tax cannot be done without filing a final tax return or Municipal Resident Tax declaration. Even if your income was low last year and you are not required to file a final tax return or Municipal Resident Tax declaration, filing a declaration may make you eligible for a reduction in the National Health Insurance Tax or lower your out-of-pocket limit for Medical Expenses (all members, including the presumed household head, must file). Please be sure to file a declaration regardless of whether you have income or not (those receiving survivor's Pension must also file).
Those who have not yet filed a declaration and have been living in Inagi City since before January 1, 2026, please complete the declaration procedure at the Taxation Division.
For those who moved in on or after January 2, 2026, please file a declaration with the municipality where you resided as of January 1, 2026, and notify the National Health Insurance Section accordingly. By bringing a certificate of taxation or non-taxation, the information can be reflected.

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Reduction and Exemption of National Health Insurance Tax

Income-based Reduction

If the total income of households enrolled in the National Health Insurance is below the reduced standard income in the table below, the National Health Insurance Tax will be reduced. If the income of all household members can be verified by the city and the conditions are met, the reduction will be applied automatically.

• Note: The total income includes the income of household heads (deemed household heads) who are not members of the National Health Insurance.
• Note: If there are individuals who have not declared their income, they will not be eligible for the reduction, so please be careful.

Total Amount of Income and Other Earnings	Content of Reduction
Below 430,000 yen (Note)	70% reduction on the per capita levy and the per capita levy for those aged 18 and over
Below 430,000 yen + (310,000 yen × number of National Health Insurance members) (Note)	50% reduction on the per capita levy and the per capita levy for those aged 18 and over
Below 430,000 yen + (570,000 yen × number of National Health Insurance members) (Note)	20% reduction on the per capita levy and the per capita levy for those aged 18 and over

Note: If the number of salaried workers, etc. exceeds 2, add 100,000 yen × (number of salaried workers, etc. − 1) to the amount in the table.
"Number of Salary Earners, etc." refers to the total number of persons who have employment income (limited to those whose income from salary, etc. exceeds 550,000 yen) and persons who have income related to public Pension, etc. (limited to those under 65 years old whose income from public Pension, etc. exceeds 600,000 yen, and those 65 years old or older whose income from public Pension, etc. exceeds 1,100,000 yen).

(Example) In the case of the following household (4 people)

• Household Head (Self-Employed) Income: 1.5 million yen (Business Income)
• Wife (Part-time) Income: 750,000 yen (Salary Income)
• Child (Student) Income: None
• Child (Student) Income: None

Total income amount = 1.5 million yen + 750,000 yen = 2.25 million yen

• Income threshold for 70% reduction = 430,000 yen + 100,000 yen × (1-1) = 430,000 yen (less than 2,250,000 yen): ApplicableNot Applicable
• Income threshold for 50% reduction = 430,000 yen + 310,000 yen × 4 people + 100,000 yen × (1-1) = 1,670,000 yen (less than 2,250,000 yen): Not Applicable
• Income threshold for 20% reduction = 430,000 yen + 570,000 yen × 4 people + 100,000 yen × (1-1) = 2,710,000 yen (greater than 2,250,000 yen): Applicable

In this household, the flat-rate charge is reduced by 20%.

Reduction of Fixed Charges for Preschool Children

The flat-rate charge for preschool children enrolled in the National Health Insurance (insured persons who are under 6 years old as of the first March 31 after their 6th birthday) will be reduced by 50%. For FY2026, this applies to those born on or after April 2, 2020.

For households belonging to those eligible for reductions based on household income, the equal share amount for preschool children will be further reduced by 50% after applying the reduction based on household income. Additionally, no application is required to receive the equal share reduction for preschool children.

	Amount before applying the equalization reduction for preschool children	Reduction Amount
No reduction in the uniform tax based on household income	Medical Portion 36,800 yen Support Fund Portion 14,400 yen Child Portion 1,820 yen	Medical Portion 18,400 yen Support Fund Portion 7,200 yen Child Portion 910 yen
20% Reduced Household	Medical Portion 29,440 yen Support Fund Portion 11,520 yen Child Portion 1,456 yen	Medical Portion 14,720 yen Support Fund Portion 5,760 yen Child Portion 728 yen
50% Reduced Household	Medical Portion 18,400 yen Support Fund Portion 7,200 yen Child Portion 910 yen	Medical Portion 9,200 yen Support Fund Portion 3,600 yen Child Portion 455 yen
70% Reduced Household	Medical Portion 11,040 yen Support Fund Portion 4,320 yen Child Portion 546 yen	Medical Portion 5,520 yen Support Fund Portion 2,160 yen Child Portion 273 yen

Reduction and Exemption Due to Transition to the Late-Stage Elderly Medical Care System

Reduction due to specific same household eligibility

When a person turning 75 transitions from National Health Insurance to the Late-Stage Elderly Medical Care system, and those under 75 continue to be enrolled in National Health Insurance
When determining the reduction of the National Health Insurance Tax, the income and number of Late-Stage Elderly who have transitioned are included in the assessment of reduced income.

Reduction and Exemption for Former Dependents

If a person turns 75 and transitions from the employee insurance of their company to the Late-Stage Elderly Medical Care system, and their dependents (aged 65 to 74) will newly enroll in the National Health Insurance.
For those who have newly enrolled in the National Health Insurance, the income-based portion will be exempted, and the per capita rates (medical portion, support fund portion, child portion) and the per capita rate for those aged 18 and over will be halved for two years starting from the month of the qualification acquisition date.

Support for those who have lost their jobs due to bankruptcy, dismissal, or termination

Please see the next page.

• Individuals who have been laid off, dismissed, or terminated due to bankruptcy or other reasons

Other Exemptions

Households affected by disasters (such as earthquakes or fires), households with severe illnesses, or those with other special circumstances resulting in no or significantly reduced income for the year (households in financial distress), may be eligible for a reduction or exemption of the National Health Insurance Tax if paying the tax becomes difficult. This is determined comprehensively, including the status of owned assets and living conditions. Please note that for households in financial distress, the reduction or exemption applies only to the income-based portion of the tax.
When applying for a reduction or exemption, you must submit the Application Form by the payment deadline.

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For those who have moved in and joined

Those who moved into Inagi City and joined the National Health Insurance on or after January 2, 2026, will have their income amount, which is the basis for calculating the National Health Insurance Tax, unknown, so inquiries will be made to their previous place of residence. Therefore, additional National Health Insurance Tax may be charged once the income amount is determined (in this case, an additional payment slip will be sent later).

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How to Pay the National Health Insurance Tax

The annual National Health Insurance Tax (FY2026) is to be paid in nine installments. Please make your payments using the payment slips sent to you at the designated financial institutions in Inagi City, collection agent financial institutions, convenience stores, City Hall, or the Hirao and Wakabadai Branch Offices.
The payment deadline is as follows. The withdrawal date for account transfers is also the same day.

Term	Due Date	Issuance Period of Payment Slips	Date of Notification Reflected in Taxation Details
Term 1	July 31, 2026	Mid-July 2026	Until June 22, 2026
2nd Term	August 31, 2026	Mid-August 2026	From June 23 to July 15, 2026
3rd Term	September 30, 2026	Mid-September 2026	From July 16, 2026 to August 17, 2026
4th Term	November 2, 2026	Mid-October 2026	From August 18 to September 15, 2026
5th Term	November 30, 2026	Mid-November 2026	From September 16, 2026 to October 15, 2026
6th Term	December 25, 2026	Mid-December 2026	From October 16, 2026 to November 16, 2026
7th Term	February 1, 2027	Mid-January 2027	From November 17, 2026 to December 15, 2026
8th Term	March 1, 2024	Mid-February 2024	From December 16, 2023 to January 15, 2024
9th Term	March 31, 2027	Mid-March 2027	From January 16, 2027 to February 15, 2027

Note: Depending on the enrollment status, there may be individuals whose payment frequency does not become 9 times.

Designated Financial Institution of Inagi City

Mizuho Bank Inagi Central Branch and Main Branch

Collection Agency Financial Institutions (Branches)

Kiraboshi Bank, Yamanashi Chuo Bank, Sawayaka Shinkin Bank, Jonan Shinkin Bank, Tama Shinkin Bank, Chuo Labor Bank, Tokyo Minami Agricultural Cooperative, various agricultural cooperatives in Tokyo (excluding islands), Japan Post Bank "Tokyo, Kanto Prefectures, Yamanashi Prefecture"

Direct debit is convenient for payments. For more details, please see the direct debit procedure page.

Convenience Stores

Kurashi House, Three Eight, Seikatsu Saika, Seven Eleven, Daily Yamazaki, FamilyMart, Poplar, Mini Stop, Yamazaki Daily Store, Lawson, MMK Installation Stores

Note: If the amount exceeds 300,000 yen, if the amount has been corrected, if there is no barcode printed, if the barcode cannot be read, or if the handling deadline has passed, payment at convenience stores is not possible.

Payment of local taxes using the unified QR code (eL-QR)

For more details, please see the page on "Using the Unified Local Tax QR Code (eL-QR) for Tax Payment."

• Guide to Tax Payment Using Local Tax Unified QR (eL・QR)

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About Pension Deductions for National Health Insurance Tax

For those who have their Pension deducted (special collection), the tax amount will be listed in the special collection section of the tax payment notice, and the National Health Insurance Tax will be deducted from the Pension.

The individuals subject to pension deductions are household heads aged 65 to 74 who meet all of the following criteria.

• The head of the household is a member of the National Health Insurance.
• All insured persons under the National Health Insurance in the household are 65 years old or older.
• The annual amount of the pension subject to pension deduction is 180,000 yen or more, and the National Health Insurance Tax combined with the Long-Term Care Insurance premium does not exceed half of the pension amount.

(Specific examples that are not subject to pension deductions)

• There are insured persons under the National Health Insurance who are under 65 years old in the household.
• The head of the household is 75 years old or older.

Those who meet the requirements for Pension deduction can choose either Pension deduction or bank transfer.

If you wish to use direct debit, the start date for the direct debit may vary depending on the application timing, so please contact the National Health Insurance Section before applying.

Payment methods for those subject to pension deductions

Those who pay by payment slip

From October, payments will be switched to Pension direct debit.
Payment is by payment slip in July, August, and September.

For those who pay by direct debit

Direct debit will continue after October.
Please consult us if you wish to have your Pension deducted automatically.

For those who have been paying by Pension deduction continuously since before FY2025

Pension deductions will continue.

Payment methods for those not subject to pension deductions

Payment can be made either by payment slip or by direct debit.
If you are paying by Pension deduction and no longer meet the requirements, your payment method will be switched to payment slip or bank transfer.

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If you do not pay the National Health Insurance Tax

If you delay the National Health Insurance Tax for a long period

• If the payment deadline for the National Health Insurance Tax is missed, reminders will be issued, and late fees will be collected.
• If you are eligible for special medical expense benefits and visit a medical institution, you will be responsible for 100% of the medical expenses.
• Benefits of the National Health Insurance will be completely or partially suspended (such as medical expenses and high-cost medical expenses benefits will be suspended).
• The withheld benefits may be applied to the overdue National Health Insurance Tax.
• If you continue to default on payments and do not respond to tax consultation, you will face measures such as the seizure of assets.

If it is difficult to make the payment by the due date, it may be possible to pay in installments, so please consult the Collection Division's Delinquent Payment Section as soon as possible.

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