Understanding the Gap Between National Health Insurance and Employees’ Health Insurance#

For foreign residents planning a long-term future in Japan, understanding the nuances of the health insurance system is as critical as maintaining a valid visa. One of the most confusing aspects of this system occurs during the transition between jobs—specifically, switching from National Health Insurance (NHI or Kokumin Kenko Hoken) to Employees’ Health Insurance (EHI or Shakai Hoken), or vice versa.

Questions often arise regarding the so-called “gap period” or “blank period” during these transitions. Is it permissible to have a gap? What happens if you get sick during this time? How does this affect Permanent Residence applications? This article provides an objective and detailed explanation of how to handle these transitions properly and why strict compliance is essential for your immigration status.

Japan’s Universal Health Care System#

First, it is essential to understand the foundation of the Japanese medical system: “Universal Health Insurance Coverage” (Kokumin Kai-hoken). Under Japanese law, every resident—regardless of nationality—must be enrolled in a public health insurance scheme.

Broadly speaking, there are two main categories:

1. Employees’ Health Insurance (EHI / Shakai Hoken): For regular employees of companies.
2. National Health Insurance (NHI / Kokumin Kenko Hoken): For the self-employed, unemployed, students, and those working part-time hours that do not qualify for EHI.

Because the system mandates universal coverage, a legal “gap” where you are enrolled in neither system is not permitted. If a gap appears to exist, it is typically viewed as a procedural failure or a period of delinquency, both of which can have serious consequences.

The Two Types of “Gaps”#

When people worry about a “gap period,” they are usually referring to one of two distinct situations. It is vital to distinguish between them to take the correct action.

1. The “Cardless” Period (Physical Gap)#

This scenario commonly occurs immediately after starting a new job. Your coverage under the new company’s Employees’ Health Insurance effectively starts on your first day of employment. However, issuing the physical health insurance card takes time—often two to four weeks.

During this waiting period, you have returned your NHI card to the city hall, but you have not yet received your EHI card. While you may feel anxious, you are not uninsured. Your coverage is active retroactively to your start date.

How to access medical care during this time:

• Upfront Payment: You can pay 100% of the medical costs at the clinic. Once your new card arrives, you can apply for a refund (usually 70% of the cost) through your insurance provider.
• Certificate of Coverage: In urgent cases, you can ask your employer to procure a “Certificate of Health Insurance Coverage” (Kenko Hoken Hihokensha Shikaku Shomeisho) from the Pension Office, which serves as a temporary substitute for the card.

2. The Period Between Jobs (Procedural Gap)#

The more critical issue arises when there is a time lag between leaving one job and starting the next.

For example, suppose you resign from Company A on March 20th and start at Company B on April 1st.

• Your insurance with Company A ends on March 21st (the day after resignation).
• Your insurance with Company B begins on April 1st.

For the period from March 21st to March 31st, you are legally required to enroll in National Health Insurance at your local municipal office. Even though it is only for 10 days, you cannot simply “skip” insurance.

Premiums and the “End of Month” Rule#

Many residents hesitate to enroll in NHI for short periods, fearing double payments or unnecessary hassle. However, understanding how premiums are calculated clarifies why enrollment is necessary and fair.

Health insurance premiums in Japan are generally assessed based on your status on the last day of the month.

• Scenario A (Crossing the month): If you quit on March 20th and start a new job on April 1st, you are unemployed on March 31st. Therefore, you must pay the NHI premium for the month of March. You will not pay EHI premiums for March (since you left before the month ended). There is no double payment; you simply pay NHI instead of EHI for that specific month.
• Scenario B (Within the same month): If you quit on March 10th and start a new job on March 25th, you are enrolled in EHI on March 31st. Therefore, you generally owe EHI premiums for March, and you will not be charged for NHI for March. However, you are still technically required to report the transition to the city hall to maintain accurate records.

Impact on Immigration and Permanent Residence#

For foreign residents, the implications of these gaps extend far beyond medical care. The Immigration Services Agency of Japan places immense weight on compliance with social insurance obligations, particularly when reviewing applications for Permanent Residence (PR) and Naturalization.

When applying for PR, you must submit proof of pension and health insurance payments for the past several years. Immigration officials look for:

1. Gaps in enrollment: Periods where no insurance was paid.
2. Delinquent payments: Periods where premiums were paid after the deadline.

If you ignored the NHI procedure during a two-week break between jobs, the record will show a period of non-enrollment. While you can often pay retroactively, a history of “non-enrollment” or “late payment” suggests a lack of compliance with Japanese law. This can be a primary reason for the denial of a PR application. The authorities expect applicants to understand and follow the system proactively.

Step-by-Step Procedure for Switching#

To ensure a clean record and continuous coverage, follow these steps when changing employment:

1. Upon Resignation: Receive a “Certificate of Loss of Qualification” (Shikaku Soshitsu Shomeisho) from your former employer. This document proves when your EHI coverage ended.
2. Visit City Hall: Within 14 days of your resignation, take the certificate and your Residence Card to the National Health Insurance section of your local municipal office. Enroll in NHI.
3. Pay Premiums: If you receive payment slips for the interim period, pay them immediately.
4. Starting the New Job: Your new company will enroll you in EHI.
5. Exit NHI: Once you receive your new EHI card, you must go back to the city hall to formally withdraw from NHI. This does not happen automatically. If you fail to do this, you may be billed for both insurances simultaneously. Bring your new card and the NHI card to the city hall to complete the switch.

Conclusion#

The “gap period” when switching health insurance from National Health Insurance to Social Insurance involves both the practical inconvenience of waiting for a new card and the legal obligation to cover any days between employment contracts.

While it may seem burdensome to visit the city hall to enroll in NHI for only a few weeks, doing so is mandatory under Japanese law. For foreign residents, strictly adhering to these procedures is not just about healthcare access; it is a vital component of maintaining a stable residency status and building a successful case for future Permanent Residence. Ensuring there are no unexplained blanks in your insurance history demonstrates your reliability and integration into Japanese society.