Judgment of the Court (Second Chamber) of 12 March 2026.#K. M. H. v Obshtina Stara Zagora.#Reference for a preliminary ruling – Citizenship of the Union – Article 21(1) TFEU – Right to move and reside freely within the territory of the Member States – Impediments – Request to amend gender data in the civil status registers – Directive 2004/38/EC – Article 4(3) – Article 7 of the Charter of Fundamental Rights of the European Union – Right to respect for private and family life – Obligation, for a court of a Member State, to comply with the case-law of the constitutional court of that State – Interpretation in conformity with EU law.#Case C-43/24.