The Grammarphobia Blog

Need a PhD to pluralize “master’s degree”?

Q: I’ve been asked to edit some policy papers for the graduate dean at the university where I teach. My inclination is to change “Masters degree” to “Master’s degree.” Do you have an opinion? Also, after reading through some rather convoluted arguments on the Web, I’m at sea over how to punctuate “I have two Master’s degrees.” Do you have a clear explanation of the issue?

A: On our blog, we follow The Chicago Manual of Style (16th ed.), and use the apostrophe: “master’s degree.”

We also lowercase “master’s” when used generically (as in “My son is working on a master’s degree”).

Note that when you pluralize the phrase as a whole, only “degree” gets the plural “s.” The possessive adjective “master’s” doesn’t itself become plural.

So that sentence you’re editing should be written this way: “I have two master’s degrees.”

This practice is also followed in publications of the Modern Language Association.

For example, here’s a sentence from a paper published by the MLA last June (“Rethinking the Master’s Degree in English for a New Century”): “Across all fields of study, the number of master’s degrees granted between 1980–81 and 2007–08 increased 111%, from 295,731 to 625,023.”

We wouldn’t be surprised if the master’s and bachelor’s degrees lost their apostrophes someday, just as the abbreviations—MA and BA—have lost their periods.

Punctuation does tend to fall away over time, as with USA, MD (for medical doctor), USA, NFL, and so on.

But for now, the apostrophe is still used with those degrees in the Chicago Manual as well as in standard dictionaries, including The American Heritage Dictionary of the English Language (5th ed.) and Merriam-Webster’s Collegiate Dictionary (11th ed.).

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