Many Thai immigrants in Japan understood why health insurance matters and viewed it positively. Yet almost half reported having no insurance—and people without clear residency status were especially unlikely to have it. Japan is home to close to two and a half million immigrants, and that number is rising.

Yet little is known about how easily immigrants can reach healthcare. Thai nationals offer an important window into that question because more than fifty thousand registered Thai nationals live in Japan, alongside more than seven thousand Thai nationals living there without legal residency status.

The study therefore set out to describe the health and living conditions of this vulnerable group and examine what is linked with health insurance knowledge, attitudes, and practice. So the survey reached Thai nationals aged twenty or older living in Tokyo and nearby prefectures, including Ibaraki and Chiba.

The questionnaires were collected mainly at public religious events, where vulnerable Thai nationals, including people without insurance, had a high opportunity to participate. The everyday picture was mixed: thirty-seven point three percent were enrolled in National Health Insurance, and nineteen point four percent in Social Insurance, while forty point three percent reported having no insurance.

In this group, forty point three percent reported having no insurance, while forty-one point eight percent had been diagnosed with diseases. And seventy-nine point one percent needed to communicate with healthcare providers in Japanese when receiving care, while information mostly came from friends, family, and non-government social-network sources.

The survey found that thirty-two point eight percent had an unspecified visa status, and forty point three percent were uninsured. At the same time, eighty-six point four percent expressed positive attitudes toward health insurance. The problem was not simply that people rejected insurance.

The study described Thai immigrants as having high knowledge and positive attitudes toward health insurance, while almost half reported holding no health insurance. Financial and language barriers could explain the high proportion without insurance, even when people understood its value.

The comparison found that people with more than a high-school education had higher health-insurance knowledge, as did people who had stayed in Japan longer than five years. People with unspecified visa status had lower health-insurance practice, with an adjusted odds ratio of zero point zero two, according to the analysis.

The overall finding was stark: people without legal residency status had low insurance practice despite high knowledge and positive attitudes toward health insurance. Some documented immigrants were uninsured too, and some participants experienced costly medical events.

Lack of residency status could keep people outside Japan’s healthcare coverage and prevent appropriate care. Understanding the system may not be enough: vulnerable Thai foreigners, especially those without legal residency, had low insurance practice despite high knowledge and positive attitudes.

The study calls for healthcare coverage that includes immigrants and further identification of people at high risk, so support can reach them. The barrier is not simply a lack of knowledge or concern. This study points to language, money, and residency status as obstacles that can leave people unable to use healthcare when they need it.