Short answer: often yes, but it depends entirely on where you apply. In the United States and Canada, going straight from a bachelor's degree into an AI or computer science PhD is the normal path, not an exception. In most of continental Europe, including Germany, the Netherlands, and France, you generally need a master's first, because the PhD there is a salaried research job rather than a taught degree. The UK sits in the middle. This piece walks through the split country by country, explains why the models differ, and gives you a green, amber, red view so you can aim your applications sensibly.
One caveat up front: this is informational, not legal, immigration, tax, or financial advice. Admission rules vary by university and even by lab, so treat everything here as a starting map and verify each program yourself.
What direct bachelor's-to-PhD actually means
In the North American model, a PhD is a long program (typically five to six years) that includes coursework, qualifying exams, and then research. Because the taught component is built in, you do not need a separate master's to enter. Many strong applicants apply in their final undergraduate year. At MIT, for example, the department admits people straight from a bachelor's and has them earn the master's on the way to the PhD, since there is no standalone terminal master's to apply to (the official MIT EECS graduate admissions FAQ).
The European model is different. There, a PhD is usually a fixed-term employment contract: you are hired to do research on a funded project, paid a salary, and expected to already have the research training a master's provides. That training is the master's degree, so the master's becomes a prerequisite rather than something you pick up along the way. The UK blends both: some routes want a master's, but integrated PhD and Centre for Doctoral Training (CDT) programs bundle a taught first year, and an MRes-then-PhD path is common.
Why the funding model decides the answer
The pattern is not random. It follows the money.
- Salary-funded systems ask for a master's. In Germany, the Netherlands, and much of the Nordics, a PhD candidate is an employee on a research contract. Employers want someone ready to produce results, so a research master's is the standard entry ticket.
- Coursework-funded systems build the training in. US and Canadian PhDs fund students through teaching and research assistantships and add one to two years of graduate courses. The master's-level training happens inside the PhD, so entering from a bachelor's works fine.
- Mixed systems offer both doors. The UK's integrated and CDT routes add a taught year for people without a master's, while direct DPhil entry stays open to exceptionally strong bachelor's graduates.
If you want the deeper funding and stipend picture for the European side, see our companion piece on AI PhDs in Germany, Switzerland, and the Netherlands.
Green, amber, red: a country view
Here is the rough state of play as of 2026. "Green" means direct bachelor's entry is common and expected, "amber" means it is possible through specific routes, and "red" means a master's is generally required first.
- Green (direct entry normal): United States and Canada. Apply in your final undergraduate year.
- Amber (possible via specific routes): United Kingdom, through integrated PhDs, CDTs, or a strong four-year undergraduate degree. Oxford, for instance, will consider a first-class or strong upper-second four-year bachelor's on its own, or a three-year degree paired with a master's (the official Oxford DPhil in Computer Science page). Switzerland is also mixed: some groups hire bachelor's-holders into a fast-track, but a master's is the safer assumption.
- Red (master's usually required): Germany, Netherlands, France, and most of continental Europe, where the PhD is a paid research post.
Pan-European networks like ELLIS run structured PhD tracks that mostly assume a master's; if that route interests you, read how the ELLIS PhD program works and how to apply.
How to strengthen a direct-entry application
If you are aiming for a green or amber country without a master's, the bar is real research potential, shown rather than claimed. Work through this over the next few weeks:
- Get research experience on record. A summer in a lab, an undergraduate thesis, or a research internship matters more than grades alone. Admissions committees are betting on whether you can produce novel work.
- Aim for a publication or a preprint. Even a workshop paper or a solid arXiv preprint signals you can carry an idea to completion. One real contribution beats a stack of course certificates.
- Line up strong letters from researchers. Two or three recommenders who can speak to your research ability, ideally people whose names the committee recognizes, carry enormous weight.
- Email potential advisors early. In Europe especially, PhDs are advertised positions. A short, specific message about their recent work, sent before the deadline, often decides the outcome.
- Match your target country to your profile. No master's and no time to get one? Weight your list toward the US, Canada, and UK integrated routes. Have a research master's already? Europe's funded posts open up.
Choosing between all of these countries at once is exactly the comparison our the AI Relocation Guide is built for. You can also compare all 21 countries on stipends, visas, and years-to-residency side by side.
The honest takeaway
The choice is less about prestige and more about matching your current stage to a system that will take you.
- Fresh bachelor's, strong research signal: the US and Canada are your natural home. You lose nothing by skipping a separate master's.
- Bachelor's but a thinner research record: a UK integrated PhD or CDT, or a one-year research master's first, buys you the training and the credential.
- Already hold a research master's: Europe's salaried PhD posts are efficient, well-paid, and often faster to finish.
Whatever the country, verify the exact rule on the specific department's admissions page before you invest in an application. The general pattern is reliable; the fine print is where surprises live.
Rule of thumb: no master's yet? Aim North America or a UK integrated route. Master's in hand? Europe's funded PhD posts are yours to take.
