A research study entitled “The Result of Capability Development of Language Coordinators' on Foreign Workers' Health Insurance, Chiang Rai Province” aims to provide foreign workers with access to health insurance by developing the capability of language coordinators on foreign workers health insurance and to provide foreign workers with knowledge of foreign labor health insurance. The samples were 120 language coordinators from Muang Chiang Rai District and Mae Sai District and a random survey of knowledge on foreign worker health insurance of 385 people. Survey tools used included general information query, before-after training knowledge quiz, knowledge evaluation form on foreign workers' health insurance, Supervising and tracking form as well as the collection of migrant worker’s health insurance registration statistics. Statistics used for analysis; descriptive statistics were frequency, percentage, mean and standard deviation, the inferential statistics are t-test. The results of the study showed that the capability development of the language coordinators in health insurance for foreign workers in Chiang Rai: starting with the survey of the language coordinators with required qualifications and setting up training sessions according to health insurance guidelines of the Ministry of Public Health. Most of language coordinators were 20-29 years of age, male, primary education qualification, freelance workers with monthly income from 5,000-10,000 baht, and were language coordinators based in Thailand for 5-9 years. Before the training, the language coordinators had a low level of knowledge and after the training they have a high level of knowledge. The test scores before and after the training were significantly different with statistical significance at the level of .05 After the training, the language coordinators' performance was monitored and supervised with result indicating that the most seek-for-advice topics were the benefits of health insurance, rates, required documents for health examination and health insurance, change of medical facility eligibility according to work location, and verification of health insurance eligibility. For the registration of health insurance of migrant workers, it was found that more foreign workers registered for health insurance cards after the development of capability of language coordinators. In assessing the knowledge of foreign workers on health insurance with the support of the trained language coordinators, it was found that foreign workers had a moderate level of knowledge of health insurance. The results of the research can be used to guide the development of language coordinators in other areas of Thailand. As a result, migrant workers have more access to health insurance.