The government has launched a nationwide probe into allegations that foreign residents are abusing the public health insurance system, according to sources familiar with the matter.

The Health, Labor and Welfare Ministry is checking with municipalities to investigate cases involving foreign visitors who inappropriately acquired residential status to make themselves eligible for public health insurance so they can skirt costly medical fees, the sources said.

The ministry will compile the findings this autumn and discuss prevention steps. The insurance system was not originally designed to take into account a time when foreign people would be receiving medical services.

Japan had about 2.56 million foreign residents at the end of 2017, a number that has climbed every year since 2013, according to the Justice Ministry. Nearly half are Chinese and South Koreans, at 29 percent 18 percent, respectively, with Vietnamese and Filipinos following at 10 percent each.

Since the government plans to rely more on foreign labor to compensate for Japan’s labor shortage and shrinking population, the number of foreign residents is expected to grow. Tokyo reportedly expects Japan to have more than 500,000 foreign workers by 2025.

In Japan all residents, including foreigners, must enroll in a health insurance plan provided by their employers, which also covers their dependents, or enroll in the national health insurance program at their local municipal office.

Even if they are not company employees, those who stay in Japan for three months or longer for business or study purposes can apply for national health insurance.

But there have been a string of cases in which non-Japanese have fraudulently obtained residency status, for example, by posing as international students.

In other cases, visitors whose claims of family ties with foreign residents of Japan were deemed questionable have visited Japan for medical treatment.

The national health insurance program requires that policyholders shoulder 30 percent of their medical costs, in principle. The remainder is covered by the policy, which is funded by the payment of monthly premiums.

By taking advantage of the benefits of a special Japanese scheme for exorbitant medical bills that caps the size of monthly payments, policyholders can reduce the cost of expensive treatments by several tens of thousands of yen a month.

A Chinese man in his 60s made himself one such beneficiary of the scheme.

Shortly after coming to Japan, the man visited a hospital in Tokyo last summer, accompanied by his son, who resides here. The man was listed as a dependent, thus entitling him to health insurance benefits.

After undergoing surgery and postoperative chemotherapy, his medical bill came to ¥3 million. But thanks to the special scheme, he only paid ¥80,000 and promptly returned to China, leaving the insurance system to pay the rest.

Experts believe such practices, whereby people who have never paid insurance premiums can receive expensive medical treatment on the cheap, hurt the public health insurance system.

Yoneyuki Kobayashi, director of AMDA International Medical Information Center, said the system, which allows the special payment-capping scheme to be applied to those who have just entered Japan, should be reviewed.

At the same time, however, Kobayashi said foreign people should be able to receive standard medical services in the country.

“Discriminating against foreigners is out of the question but the current insurance system can lead to reverse discrimination against Japanese people,” Kobayashi said.