There are two categories of membership in the Order: Justice, for individuals able to submit nobiliary proofs, and Magistral Grace for all others. Christians may be admitted in the following grades: Member, Officer, Commander, Knight or Dame, Knight or Dame Commander, Knight or Dame Grand Cross.

The category of Justice is restricted to postulants who have proved hereditary nobility from each of his/her four grandparents or, when paternal line alone is used, from a paternal great-grandfather. Those members who are unable to furnish proof of hereditary nobility will be admitted in the category of Grace. According to ancient traditions, ecclesiastical members holding the rank of a Cardinal within the Holy Roman Catholic Church may also be admitted in the category of Justice.

As a mark of the Grand Master’s special esteem, the Order may also award a Collar to a head of State and very occasionally to its high dignitaries. The Order also confers decorations of merit to its members and to individuals not necessarily members of the Order who have contributed, by their service, to its humanitarian work.

The Military and Hospitaller Order of St Lazarus is not an order of merit, but an order of chivalry, open to people baptised into the Christian faith. It has seven grades, which are, in ascending order, member, Officer, Commander, Knight/Dame, Knight/Dame Commander, Knight/Dame Grand Cross, and Knight/Dame Grand Cross with Grand Collar.

The clergy of Christian churches are admitted as Chaplains of the Order, with the grades of Assistant Chaplain, Chaplain, Senior Chaplain. Bishops may be given the grade of Ecclesiastical Grand Cross of the Order.

Promotion depends on the member’s contribution to the work of the Order. It is not based on specific acts, or time spent in any one grade of the Order.