Health cover for PhD students

SSN: on a study permit, voluntary registration with the national health service costs €700 per calendar year if your only income is scholarships (University of Bologna). It runs 1 January to 31 December, cannot be split or backdated, and gives you a family doctor (Ca' Foscari guide).
Private: accepted for the permit if it covers urgent hospital care with no limits (MUR circular).
With a November start, a €700 SSN payment covers only November and December. Many students use a private policy until January, then register with SSN.

This page explains official rules in plain language. I am not an immigration adviser and I do not give visa advice. For that, always use official government sources. Rules change: confirm with your university, the embassy and VFS before you act.