You are entitled to reimbursement if the treatment is part of the Dutch basic healthcare package or the Long-Term Care Act (Wlz).
Do you need intensive care and supervision all day long? Then you may be entitled to long-term care. For that care you need a so-called indicative decision. You can request this from the Care Assessment Centre (CIZ.nl, Dutch only). You can do that before you come to the Netherlands.
The CIZ will examine whether you can get care from the Wlz. The CIZ also determines what kind of care and how much. You will receive a message from the CIZ within 6 weeks. Do you not agree with that decision? Then you can object to the CIZ.
Are you receiving long-term care? And do you stay in a Dutch institution for a long time? Then you will be officially living in the Netherlands again. In that case, you are no longer subject to treaty law.