In North America, the Master of Theology (Latin: Theologiae Magister, abbreviated ThM) is a post graduate or doctoral degree considered by the Association of Theological Schools to be the minimum educational credential for teaching theological subjects in accredited seminaries and graduate schools. The ThM is equivalent to the Master of Sacred Theology and the Association of Theological Schools classifies both degrees as "Advanced Programs Oriented Toward Theological Research and Teaching."
A Master of Theology (ThM) is an advanced theological research degree offered by universities, divinity schools, and seminaries. The degree is usually earned after the Master of Divinity (MDiv) or an equivalent of three years of graduate studies in theology. This degree can range from one or two years of specialized advanced studies in theological research (i.e. Counseling, Church History, Systematic Theology, etc.). It may or may not require comprehensive subject exams and a research thesis, but is required to produce "learning outcomes that demonstrate advanced competency in one area or discipline of theological study and capacity to conduct original research in that area." The Master of Theology is usually designed as an advanced academic degree with an emphasis on academic research. The ThM often functions as a terminal and/or doctoral level degree, dependent upon one's particular educational route or institution of study. Some institutions award a ThM en route to a Doctor of Philosophy in addition offering stand alone ThM programs.
See link for a comparison of the ThM to other seminary degrees - https://www.seminarycomparison.com/seminary-comparison-mdiv-vs-ma-vs-thm/