A former student is suing her university for \$1.3m (£838,000) in lost earnings, after she received a C grade that kept her from landing her dream job.
Megan Thode claims the mediocre mark from Lehigh University in Bethlehem, Pennsylvania prevented her from becoming a licenced therapist.
The 27-year-old is also suing her professor and demanding a grade change.
The university contends the lawsuit is without merit but a judge in Northampton County declined to dismiss the case, ruling there was enough evidence to proceed.
Her professor, Amanda Eckhardt, stands by the C+ grade.
She says the student failed to behave professionally and scored zero out of 25 for class participation, which bumped down her overall performance.
"I ... believed she received the grade she earned," Ms Eckhardt said.
The result prevented Ms Thode - an otherwise A grade student - from advancing to the next stage of her professional therapist studies in 2009, local newspaper the Express-Times reported.
She wound up getting a master’s degree in human development instead.
Her lawyer argues she was targeted in class because she is an outspoken advocate for gay marriage.
Her professor claims the student had outbursts in class, did not participate appropriately, was emotionally unstable and failed to heed a warning letter.
Her father Stephen Thode, who is a finance professor at Lehigh University, testified on her behalf and said her participation score was highly irregular.
"I have never heard of a case, not just at Lehigh, where a student achieved a zero in class participation where they attended and participated in every class," he said.
The judge is expected to issue a ruling on the lawsuit, with neither side indicating at present they are prepared to reach a settlement.