Is it appropriate to ask for a pay raise as an adjunct professor with a Master's degree? I am currently a Ph.D. student with a Master's degree. Throughout my time in grad school, I have been an adjunct at a local university. Recently, this university has started a Master's program in my field. However, the department is quite small and those faculty who are able/interested in teaching these classes is even smaller thus, I have been asked if I would like to teach one of the graduate classes for this new program. 

My question is whether or not it would be appropriate for me to ask for a pay increase to teach this course. Currently the adjunct pay is determined by a per unit rate depending on level of education (in my case Master's). What I am unsure about is if this rate should change, or if it is common in other institutions for pay to increase when teaching grad level courses.
There are myriad factors that go into pay rates, but the bottom line with this or any job is your pay should reflect what you bring to the table.  Sounds to me like you have a rarified skill that is in demand in this specific instance so yes, absolutely, ask for a pay increase.  Politely, sweetly, and prepared to hear "no."