Japan Pension & Social Insurance Contributions: Payments, Back Payments and Tax Relief

Systems covered: National Pension, Employees’ Pension and statutory health insurance.

Required payments: pension and health are separate

The standard National Pension premium is ¥17,920 a month for April 2026–March 2027; that amount does not identify your category or price an old debt. Employees’ Pension uses recorded remuneration and bonuses, with employer and employee funding. Ask payroll about any exemption or premium adjustment. National Health Insurance premiums or taxes depend on municipal or association rules, household circumstances and income. Obtain the actual assessment and check available reductions or deferral; do not apply one nationwide health rate.

Correct the record before considering tsuino

If paid employment or contributions are absent from your pension record, ask the pension office about record correction first. An approved exempt, deferred or student period may qualify for tsuino, generally within ten years. Partial exemptions require the unpaid remainder to have been paid; older periods can have a surcharge, and other eligibility restrictions apply. Get the accepted months and quote from Nenkin Net or the office. Compare official forecasts using the same future working assumptions; a gap alone does not show the pension increase.

Voluntary payments: check Fuka and exemptions first

Fuka adds a separate pension for eligible Category 1 or voluntarily insured people under 65. National Pension Fund membership excludes it, and iDeCo can affect the combined contribution limit. Income-based exemptions, deferral and student special payment generally exclude Fuka. Approved maternity and the new October 2026 childcare exemption have specific allowances. Qualifying Category 1 parents caring for a child under one can apply for that childcare exemption, with covered months treated as paid for basic pension. Confirm the applicable exemption before adding an optional payment.

Tax relief: the deduction is not the refund

Eligible social-insurance premiums actually paid by you, including qualifying payments for a spouse or relative sharing your livelihood, can be an income deduction. Covered categories include statutory pension and health premiums. Keep the required evidence and use the year-end adjustment or tax-return procedure that applies. The deductible premium is not an equal cash refund: the tax saved depends on your tax position. In the cost calculator, enter a confirmed cash saving only; leave it unknown when you have only a contribution certificate.

Which step should you take next?

1. Match your pension category, payroll deductions and municipal health assessment to the same payment period.
2. Resolve missing records and check exemptions before obtaining an accepted tsuino or Fuka payment amount.
3. Compare your own cash commitment, then confirm the actual tax effect and each payment deadline.

Compare your contribution costs →

Compare a specific pension option

• Fuka additional pension calculator
• Official tsuino quote and pension gain
• 日本語：付加年金・追納ガイド

What the cost calculator needs

Use Nenkin Net or pension-office quotes for tsuino and a municipal/association assessment for National Health Insurance. Keep employer premiums separate. A social-insurance deduction certificate supplies a deductible amount, not the cash tax saving field.

It adds confirmed payment amounts and separates cash tax savings from funding paid by others. It does not calculate statutory liability from salary, buy contribution years, choose an insurance product or predict pension entitlement.