The award follows the submission of a Thesis for examination: Theological and Pastoral Factors Constraining the Admission to the Eucharist of Young People with Learning Difficulties.

The Lambeth MA in Theology by Thesis was inaugurated in 1990 by Archbishop Runcie at the request of the Lambeth Diploma committee in order to provide for the possibility of theological study at a more advanced level than the existing Diploma. It was agreed that a limited number of candidates (no more than 30 at one time) should be allowed to register for the MA. These were to be graduates with honours degrees (2:1 or above) in Theology, or closely related subjects, or those who had gained the Lambeth Diploma with Distinction. The first MA by Thesis was awarded in 1993.

In 2007 the Archbishop's Examination in Theology launched the MPhil/Phd research degrees, developed with Quality Assurance Agency requirements and general university standards in mind, and the Lambeth MA is being phased out.

The Archbishop of Canterbury enjoys the right to grant such degrees by an Act of Parliament of 1533 which gave Archbishop Cranmer the right to grant dispensations previously granted by the Pope.