For example, if country X is about to offer free, universal healthcare to it citizens; is it possible to limit this right only to citizens, and exclude residents from other member states?
Short answer: it is the role of Court of Justice of the European Union to decide if some ruling follows EU law or not.
Long answer: EU citizenship is defined in the Article 20 on the Treaty of the Functioning of the European Union:
Citizens of the Union shall enjoy the rights and be subject to the duties provided for in the Treaties. They shall have, inter alia:
- (a) the right to move and reside freely within the territory of the Member States;
- (b) the right to vote and to stand as candidates in elections to the European Parliament and in municipal elections in their Member State of residence, under the same conditions as nationals of that State;
- (c) the right to enjoy, in the territory of a third country in which the Member State of which they are nationals is not represented, the protection of the diplomatic and consular authorities of any Member State on the same conditions as the nationals of that State;
- (d) the right to petition the European Parliament, to apply to the European Ombudsman, and to address the institutions and advisory bodies of the Union in any of the Treaty languages and to obtain a reply in the same language.
This is further explored in the EU Charter of Fundamental Rights.
This description is, however, quite broad but it gives just enough support to direct any possible misinterpretation to an adequate institution that can handle it. If a national government does something that can be constrained as discriminatory the Court of Justice of the European Union (CJEU) can be called into action to decide if discrimination has occurred or not (and adequately react to it). Take a look at a list of this court rulings to have an idea of how it works.
For your particular example on healthcare there can be small, very exceptional, differences. Nevertheless as a rule of thumb:
- For temporary stays:
As an EU citizen, if you unexpectedly fall ill during a temporary stay abroad - whether on holiday, a business trip or studying abroad - you are entitled to any medical treatment that can't wait until you get home. You have the same rights to health care as people insured in the country you are in.
- For long term stays:
When you move to another EU country you can get healthcare under the same conditions as other local residents. Which country's health care system ultimately pays for your medical treatment will depend on your specific situation – it will usually be your new home country, if you have moved there to work, for example.
You have the right to organise medical treatment , such as consultation with a specialist, surgery or treatment for a specific condition, in another EU country on the same terms and at the same cost as people living in that country.
However, some countries may restrict access to certain types of healthcare abroad (e.g hospital treatment or highly specialised and expensive treatment). You will also usually need prior authorisation from your health insurer before you organise your medical treatment abroad.
This evidently works because access to healthcare is part of the EU Charter of Fundamental Rights:
Everyone has the right of access to preventive health care and the right to benefit from medical treatment under the conditions established by national laws and practices. A high level of human health protection shall be ensured in the definition and implementation of all Union policies and activities.
Just as a curiosity there is an European Health Insurance Card that greatly facilitates treatment abroad.
Hardly possible. To give you an idea of the issues arising from such a proposition, here is a real life example: The Ausländermaut.
A conservative party in Germany tried to introduce road-pricing (Maut in german) for cars, which was intended to only apply to non-german citizens.
As this clearly violates the EU's priciple of non-discrimination, the proponents of this plan tried to work-around this issue by lowering the tax on cars (KfZ-Steuer) for german car owners. Thus, the Maut applies to all cars using the german highway system (the Autobahn), however, german car holders are eligible for a refund in roughly the same amount of the Maut.
Some media reports in chronological order:
It's not possible. The principal of freedom of movement of labour is that someone can go and work in another EU country without impediment, the same as goods and services can be moved/provided across borders without impediments such as tariffs or "locals only" rules.
Limiting certain rights, treatments or benefits to citizens only would be an impediment to citizens of other EU countries working there. Thus, it is not allowed.