Most health AI contract work for clinicians falls into three types, regardless of what a specific platform calls them. Understanding the difference helps you apply for the right projects and prepare more effectively for the onboarding assessment.
The three role types
AI Trainer (Clinical)
This is typically the most common entry point. You are asked to write or refine reference answers — the “gold standard” responses used to train and calibrate an AI system.
In practice that means reading a clinical scenario, writing a response that demonstrates how a competent clinician would actually reason through it, and being explicit about uncertainty, safety-netting, and when to defer or escalate. The emphasis is on realistic reasoning, not textbook completeness.
This role suits clinicians who are comfortable explaining their thought process in writing and can resist the urge to over-answer.
AI Evaluator (Clinical)
Here you are assessing AI-generated outputs rather than writing your own. Given a clinical prompt and an AI response, you score or compare it against structured criteria — covering safety, clinical appropriateness, tone, use of uncertainty, and whether the system knows when not to answer.
This role is sometimes called AI reviewer, quality rater, or safety evaluator depending on the platform. It suits clinicians with strong risk awareness and an interest in where AI goes wrong rather than just where it goes right.
Clinical Subject Matter Expert (SME)
SME roles involve providing senior or specialist judgement — typically on complex scenarios, edge cases, or situations where evaluators have disagreed. These tend to be more selective, better paid, and require demonstrable depth in a specific domain.
If you are a consultant, advanced practitioner, or experienced specialist, SME work is worth looking for specifically. Generalists can access SME roles too, particularly where the domain is undifferentiated or primary care adjacent.
Which role type suits you?
The honest answer is that you often don’t get to choose — platforms assign tasks based on your onboarding assessment results and the projects currently running. But understanding the types helps you present yourself well in the assessment and know what to expect once you start.
- If you enjoy explaining reasoning and thinking out loud in writing → Trainer roles
- If you are drawn to quality, safety, and finding what’s wrong → Evaluator roles
- If you have deep specialist experience in a specific area → SME roles
Many clinicians end up doing a mix of all three across different projects.
How opportunities are signposted
Specific projects — including eligibility criteria, indicative pay, and time commitment — vary by platform and change frequently. Current contract project work available via Mercor and Micro1 is signposted on the opportunities page.
This site explains the role types and how the work functions. The contracting relationship is entirely between you and the platforms.
Where to go next
- Am I suited to this kind of work?
- How does the onboarding and application process work?
- View current signposted contract work
Written by
Sean Key
Digital Health Senior Programme Manager · 29 years’ NHS & private sector experience
Sean has spent nearly three decades delivering complex digital programmes across the NHS and private healthcare — from LIMS and PACS deployments to primary care, urgent care, mental health, and national interoperability work. Not a clinician. His perspective is that of a practitioner who understands how digital health really gets built, procured, and adopted in the real world.