In general, the donation is kind of a personal income, which raises the question: “Will it be taxed?”
All incomes of tax individuals are subject to taxation under the Personal Income Tax Act (PITA), except non-taxable ones. A received donation is not recognized as an income; hence, it is not taxable according to art.13, par.2 of PITA.
On the other hand, properties acquired via donation are taxable according to the Local Taxes and Fees Act (LTFА). However, LTFА specifically excludes donations to EU citizens for the purposes of medical treatment as non-taxable.
As a resume: If a Bulgarian citizen receives donation for medical treatment and uses it for covering the medical expenses, then the donation shall not be subject for taxation.