Five years of unfunded summers is more than a year of salary, gone. I want you to sit with that number for a second, because everyone compares the nine-month stipend and almost nobody asks about the other three months.
The standard academic-year stipend covers nine months. Summer is the gap. Some programs extend funding through the summer automatically. Others leave you to find teaching, land an internship, or simply go unpaid. Over a five-year PhD, the difference between funded and unfunded summers is staggering. It is the easiest chunk of money in the whole comparison to miss, because it never appears in the headline.
Summer teaching is the common patch, and it is not free money. It eats the research months when you would otherwise be making dissertation progress. A summer spent teaching to survive is a summer not spent publishing, and publishing is the currency that actually matters for your career. Programs with real summer funding are buying you research time, not just cash. That distinction matters.
Internships split the difference. In CS and engineering, a summer internship can pay extremely well, sometimes more than the stipend itself. But internships are not guaranteed, they pull you away from the dissertation, and in some fields they barely exist. Do not count income you do not have. That is budgeting rule number one.
So when you line up offers, run a real PhD funding comparison on twelve-month totals, and use a stipend comparison tool in 2026 that lets you filter on summer funding instead of burying it in a footnote. Compare the twelve-month number, not the nine-month headline that makes everything look rosier than it is.
Ask the summer question explicitly: is summer funding included, automatic, or competitive? Do not accept a vague usually. Get it in writing, in the offer letter, before you sign. Filter programs by summer funding and guaranteed years at phdstipend.fyi, where the full package is laid out program by program. Your future self, the one writing a dissertation in July, will be glad you asked.