From the government's citizeninformation.ie web site:
If you are taking up residence in Ireland or returning here to live, you would be regarded as ordinarily resident in Ireland if you satisfy your Health Service Executive (HSE) that it is your intention to remain in Ireland for "a minimum of one year".
To establish that a person is ordinarily resident a Health Service Executive (HSE) may require:
- Proof of property purchase or rental, including evidence that the property in question is the person's principal residence.
- Evidence of transfer of funds, bank accounts, pensions etc.
- A residence permit or visa.
- A work permit or visa, statements from employers etc.
- In some instances, the signing of an affidavit (a sworn written statement) by the applicant.
The fact that a non-EU national has established their eligibility for health services does not automatically mean that their dependants are also eligible.
Dependants of non-EU nationals may also have to satisfy the above requirements.
An overseas student would be considered ordinarily resident in Ireland for health services purposes if he/she is attending a registered course of study of at least one academic year's duration.