Would a student be considered an Undergrad or a Grad student if the first part of the year they were an undergrad and then started grad school?

[DanielV01]

Undergrad.  The good news about the American Opportunity Credit is that when you start the year as an undergrad, even the graduate school expenses for that year do qualify for the credit.  The question (grad v. undergrad) is moot for either the Lifetime Learning Credit or the Tuition and Fees Deduction.  However, for the American Opportunity Credit, the student must be an undergraduate.  Your student's status will not disqualify him from claiming (or being claimed) for this credit, as long as the credit has not already been claimed for 4 years on this credit.  Here's some more information, taken from the following website (click on link for full page) https://www.irs.gov/newsroom/american-opportunity-tax-credit-questions-and-answers:  

Q12.  Who is an eligible student for the American opportunity tax credit?

A. For the American opportunity tax credit, an eligible student is a student who: (1) is enrolled in a program leading toward a degree, certificate or other recognized post-secondary educational credential; (2) has not completed the first four years of post-secondary education as of the beginning of the taxable year; (Italics added) (3) for at least one academic period is carrying at least ½ of the normal full-time work load for the course of study the student is pursuing; and (4) has not been convicted of a felony drug offense. 

Q13. If a student was an undergraduate during the first part of the taxable year and became a graduate student that same year, will the student qualify for the American opportunity tax credit?

A. If a student has not completed the first four years of post-secondary education as of the beginning of the taxable year, and has not claimed the Hope scholarship credit and/or the American opportunity tax credit for more than four taxable years, the student can claim the American opportunity tax credit for qualified expenses paid during the entire taxable year. (Italics added)