I am actually surprised to hear Tricare provides services outside of military installation overseas with all the foreign regulations and laws.
Tricare is run by the DOD and has no interface with local government laws overseas. Beneficiaries use the medical services from local providers and file a claim for reimbursement of the cost, minus their deductible and co-pay. Tricare then pays if the services provided are Tricare authorized/covered services. According to the Tricare manuals, Tricare is supposed to take into consideration local medical delivery customs that are different then US medical delivery.