European Union (EU) regulations determine that if a person insured by public (compulsory) health insurance in one member state cannot get the needed healthcare services in the country in which he is covered by compulsory healthare insurance, then with the prior authorisation of his competent institution (form E112 or portable document S2) he can travel to another country of the European Union, Iceland, Norway, Liechtenstein, or Switzerland and get the appropriate healthcare services in one of these countries.
There is a special Commission at the Ministry of Health of the Republic of Lithuania responsible to for taking decisions on prior authorisation. The National Health Insurance Fund (NHIF) issues the form E112 within 5 days after the Commission has taken positive decision to send the patient for examinations/consultation/treatment/ abroad.
Form E 112 (portable document S2) is a document certifying that the holder is entitled to receive certain state-provided healthcare services in any of the EU member states, Iceland, Lichtenstein, Norway or Switzerland, under the same conditions and at the same cost (free in some countries) as people insured in that country.
Please note that the NHIF and the Territorial Health Insurance Funds do not accept invoices issued by foreign healthcare providers. The cost of healthcare provided on the basis of form E112 should be covered by the local public health insurance institution of the country providing the services according to its national legislation and rates and the patient should pay co-payments. The patient's co-payments as well as expenses paid accommodation and transportation expenses will not be reimbursed from the Compulsory Health Insurance Fund's budget.
So, in order to receive health care abroad on the basis of form E112, first of all you should find out if the public health insurance covers the costs of healthcare you needed as well as if healthcare provider belongs to the country's national health system.