If you live or work in the Netherlands you have to hold a basic Dutch Basic Health Insurance Policy (Basisverzekering) within 4 months after arrival, even if you are already insured in another country. However, there are some exceptions to this rule.
You are free to choose your Health Insurance Provider and may change provider every year. In some cases, companies will offer Corporate Healthcare Insurance. Check with your employer if this applies to you.
Basic Dutch health insurance
The Basic Dutch Health Insurance Policy (Basisverzekering) offers a universal package for everyone over the age of 18 years, this is regardless of gender, age and health. It is in principle illegal for Health Insurance Companies to refuse an application or impose special conditions.
The Dutch government decides every year, what is covered and what the compulsory excess (eigen risico) is. If you don’t take out insurance while you are required to do so, you risk a fine.
Dutch Healthcare Insurance is also explained here in a simple, but comprehensive animation.
For those holiday people that need medical services: they have to pay after treatment. This amount can be reimbursed from their own insurance.