National health authorities can refuse authorisation if the treatment in question, or the healthcare provider in question, could present a risk for the patient. If the healthcare can be provided at home within a medically justifiable time limit, then authorisation can also be refused. However, Member States will need to explain why such a decision is necessary, and will need to base their assessment of what is "medically justifiable" on your individual case. (Source: EU Commission MEMO/11/32.)