For degrees, use periods between letters.
e.g., B.A., M.A., Ph.D., M.D., D.O., Ed.D., Psy.D.
John Doe, M.D.
When used after a name, an academic or religious abbreviation is set off by commas.
Rev. John Doe, S.J., gave a homily.
In an article, prefer to use Dr. John Doe vs. John Doe, M.D. upon first reference.
Upon second reference, use last name only unless a specified reason.
However, in donor lists, use John Doe, M.D.
Use an apostrophe in bachelor's degree and master's degree. But use capitalization and no apostrophe in Bachelor of Arts; Master of Science. The word degree should not follow an abbreviation.
She has a B.A. in English.
The academic discipline should be lowercase, except when this is a proper noun.
e.g., bachelor's degree in math, master's degree in English
For family suffixes, use a comma before Jr. and Sr. However, do not use for Roman numerals.
John Doe, Jr.
John Doe III
John Doe, Esq.
John Doe, Esq., graduated from a law school.