Social Security Agreements: How Your Japan Pension Credits Transfer

What are totalization agreements? — 社会保障協定とは

A totalization agreement (社会保障協定) is a bilateral treaty between Japan and another country that coordinates their pension systems. These agreements solve two major problems that foreigners face when working across borders:

• Double coverage (二重加入の防止) — Without an agreement, you might be required to pay pension premiums in both Japan and your home country simultaneously. The agreement eliminates this double burden.
• Period totalization (期間通算) — Without an agreement, you might not meet the minimum contribution period required in either country. The agreement lets you combine contribution periods from both countries to qualify for pension benefits.

Japan requires a minimum of 10 years (120 months) of pension contributions to qualify for any pension benefit at retirement. For many foreigners who spend only a few years in Japan, this threshold is impossible to reach on Japan contributions alone. Totalization agreements solve this by allowing you to count your contribution periods in your home country toward Japan's 10-year requirement, and vice versa.

These agreements are governed by the 厚生年金保険法 and individual bilateral treaty texts between Japan and each partner country. The agreements are managed by 日本年金機構 (Japan Pension Service) on the Japanese side, in coordination with 厚生労働省 (Ministry of Health, Labour and Welfare).

Countries with agreements — 協定相手国一覧

As of 2026, Japan has signed social security agreements with 23 countries. However, not all agreements include period totalization — some only prevent double coverage. The table below shows the full list.

What if your country isn't on the list? If your country does not have a social security agreement with Japan (e.g., New Zealand, Singapore, Thailand, Vietnam, most of Africa and the Middle East), you face two consequences: (1) you may need to pay pension premiums in both countries simultaneously, and (2) your Japan pension periods cannot be combined with your home country's system. In this case, the 脱退一時金 (lump-sum withdrawal) upon leaving Japan may be your best option.

How it works — 期間通算の仕組み

The totalization mechanism is straightforward in concept. When you reach retirement age and apply for a pension, the pension authority in each country looks at your total combined contribution periods across both countries to determine if you meet their minimum eligibility threshold.

Worked example: US + Japan

Let's say Sarah, a US citizen, works the following:

• 7 years contributing to US Social Security
• 5 years contributing to Japan's pension system (国民年金 or 厚生年金)

Without the totalization agreement:

• Japan: Requires 10 years minimum. Sarah has 5 years. Not eligible. Money effectively lost (aside from the lump-sum refund).
• US: Requires 40 credits (~10 years). Sarah has 7 years (~28 credits). Not eligible.

With the totalization agreement:

• Japan: 5 years (Japan) + 7 years (US) = 12 years total. Meets the 10-year minimum. Sarah qualifies for a Japanese pension.
• US: 7 years (US) + 5 years (Japan) = 12 years total. Meets the 40-credit requirement. Sarah qualifies for a US pension.

Important rules

• No double counting: If you contributed to both systems during the same period (overlapping months), that period is only counted once.
• Totalization is a last resort: The agreement only comes into play when you cannot meet the minimum period with one country's contributions alone. If you have 10+ years of Japan contributions, Japan will pay your pension without needing to invoke the agreement.
• Pension amount is proportional: Your Japanese pension is calculated based only on the premiums you actually paid in Japan. 5 years of contributions yields a much smaller pension than 40 years.
• Retirement age matters: Japan's pension starts at age 65. Your home country may have a different age. You might receive pensions from the two countries starting at different ages.

Refund vs keep — 脱退一時金 vs 期間通算

This is the single most important decision foreigners face regarding their Japan pension. When you leave Japan, you have two choices:

• Option A: Take the lump-sum refund (脱退一時金) — Get a partial refund of your contributions now, but permanently erase your Japan pension record.
• Option B: Keep your credits — Leave your contributions in the system and use the totalization agreement to eventually claim a monthly pension at retirement.

Comparison table

Decision framework

Use these guidelines to make your decision:

Take the refund (脱退一時金) if:

• Your country does not have a totalization agreement with Japan
• You contributed for only 1-3 years and the pension benefit at age 65 would be negligible
• You need the cash now and are unlikely to return to Japan
• You already have 10+ years of contributions in your home country and don't need Japan's years to qualify there

Keep your credits if:

• Your country has a totalization agreement with Japan
• You contributed for 5+ years — the pension amount becomes more meaningful
• You need the Japan years to meet the minimum eligibility in either country
• You were a 厚生年金 member with a high salary (your pension benefit could be substantial)
• You might return to Japan in the future

How to claim your pension from abroad — 海外からの年金請求方法

If you decide to keep your credits and claim your Japanese pension at retirement age, here is how the process works from overseas.

Step 1: Know your pension number

Before leaving Japan, make sure you have your 基礎年金番号 (basic pension number). This is a 10-digit number (4 digits + 6 digits) printed on your 年金手帳 (pension handbook — blue or orange booklet) or any correspondence from 日本年金機構. You will need this number to claim your pension decades later. Keep it safe.

Step 2: Verify your record

Before leaving Japan, visit your local 年金事務所 (pension office) and request a printout of your contribution history (被保険者記録照会回答票). Verify that all months are recorded correctly. Fixing errors while you are still in Japan is far easier than doing it from abroad.

Step 3: Apply at retirement age

When you reach age 65 (or earlier if you qualify for early pension at 60-64 with reduced benefits), you can claim your Japanese pension from abroad:

• Contact your home country's pension authority — In many agreement countries, you can file a single application that triggers claims in both countries. For example, US residents can contact the SSA (Social Security Administration), which coordinates with 日本年金機構.
• Or contact 日本年金機構 directly — You can mail your application to 日本年金機構 in Tokyo. The forms are available on their website, including English versions for some agreement countries.
• Required documents: Pension claim form (老齢年金裁定請求書), proof of identity, your 基礎年金番号, proof of contribution periods in your home country (issued by your home country's pension authority), and a bank account for receiving payments.

Step 4: Receive payments

Japan pays pensions bimonthly (every 2 months) on the 15th. Payments can be made to overseas bank accounts in many countries. You will need to submit a 現況届 (certificate of existence / life certificate) annually to confirm you are alive and eligible.

Double coverage prevention — 二重加入の防止

The second major function of totalization agreements is preventing double coverage — ensuring you don't pay pension premiums in two countries at the same time for the same employment.

How it works in practice

The general rule under most agreements:

• Locally hired: You pay pension premiums only in the country where you work. A US citizen hired directly by a Japanese company in Tokyo pays only Japanese pension premiums — no US Social Security tax.
• Sent by your employer (posted workers / 派遣): If your US employer sends you to work at their Japan office temporarily, you may remain in the US Social Security system only — exempt from Japanese pension premiums. This typically applies for assignments up to 5 years (some agreements allow extensions).
• Self-employed: Generally, you pay premiums in the country where you reside. Details vary by agreement.

Certificate of Coverage (適用証明書)

To prove that you are covered by your home country's pension system and should be exempt from Japanese premiums, you need a Certificate of Coverage (適用証明書). This document is issued by your home country's pension authority.

• US: Form SSA-2032 (Certificate of Coverage), issued by the Social Security Administration
• UK: Form CA3822, issued by HMRC
• Germany: Bescheinigung, issued by DVKA (Deutsche Verbindungsstelle Krankenversicherung - Ausland)
• Other countries: Contact your national pension authority for the equivalent form

You (or your employer) must present this certificate to 日本年金機構 or the Japanese employer to be exempted from Japanese pension contributions. Without the certificate, Japanese pension enrollment applies by default.

FAQ — よくある質問

Can I use totalization if I already took the 脱退一時金?

No. Once you receive the lump-sum withdrawal, the contribution periods covered by that refund are permanently erased from your record. They cannot be used for totalization. If you contributed for additional periods that were not covered by the refund (e.g., you returned to Japan later), those periods may still be usable.

What if I worked in Japan and multiple other countries?

Totalization agreements are bilateral (between two countries). If you worked in Japan, the US, and Germany, each agreement operates independently. Your US periods can help you qualify for Japan's pension (and vice versa), and your German periods can separately help too. However, the same period cannot be counted twice — if you were contributing to both the US and Germany during the same months, you choose which agreement to invoke for that period.

Does totalization affect my home country's pension too?

Yes. Totalization works both ways. Your Japan contribution periods can help you meet the minimum eligibility in your home country as well. For example, if you need 10 years of US Social Security credits but only have 7, your 5 years in Japan can help you meet the threshold.

How do I apply for the double coverage exemption?

Before or shortly after arriving in Japan, request a Certificate of Coverage (適用証明書) from your home country's pension authority. Present this to your Japanese employer or directly to 日本年金機構. The exemption is typically granted for up to 5 years for posted workers. If your assignment extends beyond 5 years, you generally must switch to Japanese pension coverage.

What if my country starts a new agreement with Japan after I leave?

If a new totalization agreement enters into force between Japan and your country, it typically applies retroactively to past contribution periods (as long as you have not already taken the 脱退一時金 for those periods). Check the specific agreement's transitional provisions, as details vary.

I'm a freelancer. Does the double coverage exemption apply to me?

The rules for self-employed individuals vary by agreement. In most cases, if you are physically residing and working in Japan as a freelancer, you are subject to Japan's pension system (国民年金) regardless of the agreement. The double coverage exemption primarily applies to employees posted by a foreign employer. Check the specific agreement for your country's rules on self-employment.

Where can I get help?

Visit your local 年金事務所 (pension office) in Japan. You can also call the 日本年金機構 general helpline at 0570-05-1165 (Japanese) or consult their website at nenkin.go.jp. For English support, some pension offices in major cities (Tokyo, Osaka, Nagoya) have multilingual staff. Your home country's embassy or consulate may also be able to provide guidance on the bilateral agreement process.