TL;DR: US expert-data platforms post $60 to $150 an hour for most licensed experts, with board-certified physicians at $115 to $150 on Mercor and coding experts at up to $150 or more on DataAnnotation. Mathematicians earn less, at $40 to $75 an hour on Mercor and $45 to $75 for xAI's US-based math tutors. A full-time domain-expert AI trainer in Asia costs $2,500 to $6,500 or more a month through Second Talent.
xAI tags its AI tutor openings "Remote International," yet each one states pay for US-based candidates alone, from $35 an hour for a language tutor to $100 for a licensed lawyer.
Expert-data platforms publish US rates and few for LatAm or Asia.
Second Talent places full-time domain-expert trainers from Asia with US startups and AI labs, shortlisted in 24 hours, with a 92% talent retention rate and 200+ teams building with us.
- 1Mercor states an average contracted rate of $97 an hour; Alignerr states $80.
- 2Mercor's listing for finance professionals based in Spain or LatAm paid $50 to $100 an hour, against $100 to $130 on its investment banking network.
- 3Prolific charges corporate buyers a 42.8% platform fee on top of the pay they set for each expert.
- 4Handshake's AI fellowship accepts experts based in the US and no one else.
Domain-expert AI trainer rates by field
Mercor runs two medical networks with different floors. A board-certified M.D. or D.O. with an active, unrestricted license sees $115 to $150 an hour. The broader medical expert network, open to any clinical credential, posts $60 to $180.
Medicine, nursing and mental health
Mental-health data pays below physician work. Mercor's psychology expert listing asked for a bachelor's degree at minimum and paid $50 to $100 an hour. The work was reviewing AI-generated content for psychological accuracy and sensitivity.
The nursing network posts $60 to $120 for patient care, medication and clinical documentation experience.
Law and finance
The lawyer network starts at $60 and reaches $150. Mercor's Legal Expert network narrows that to $100 to $150 by asking for a law degree plus a current license.
An earlier listing for US lawyers with an active bar license posted $100 to $200. Investment banking experts who build models and grade pitch materials see $100 to $130.
Coding, data and STEM
Software engineering listings on Mercor have posted $70 to $150 an hour, the widest band in the set, and data analysis experts see $70 to $120.
Chemistry experts with a graduate degree and lab or computational research experience see $65 to $105.
Mathematics sits at the bottom. Mercor's mathematics network asks for a graduate degree or an equivalent research or competition record, and says most contracts in the field have paid $40 to $75 an hour.
How DataAnnotation, xAI and Handshake price the same fields
DataAnnotation pays coders more than doctors. Its job board caps software, data science and machine learning roles at $150 or more an hour.
It puts physicians, nurses, attorneys, accountants and STEM scientists in one band at up to $125 or more.
The DataAnnotation FAQ gives the starting points behind those ceilings. Professional work in law, finance or medicine starts at $40 an hour, as do coding and STEM. General work starts at $25 to $50, and multilingual projects at $25 to $40.
Pay depends on the qualification track an expert passes, and goes out through PayPal.
xAI posts its bands on its Greenhouse job board, all for US-based candidates. Its legal and compliance tutor role asks for a J.D., active bar admission and two years of practice, for a six-month temporary contract.
Handshake AI shows the gap a task can open on one platform. Its fellowship lists software engineers with a PhD at up to $120 an hour and philosophy experts at up to $120, while an AI evaluation specialist role pays up to $17.
Two platforms state an average. Mercor lists an average contracted rate of $97 an hour and more than $4 million paid out to experts a day. Alignerr, run by Labelbox, lists an average of $80, with reviewer and evaluator roles at $40 to $120.
Outlier posts no rate on its homepage, only $500 million or more paid to experts in 50 countries.
What moves the rate inside a field
Inside one field, the license moves pay first. After that come the task, the share of the project an expert works on and the hours the buyer commits to.
- License. On Mercor, a current license lifts the legal floor from $60 to $100, and board certification lifts the medical floor from $60 to $115.
- Task. One platform can pay seven times more for one task than another: Handshake lists up to $120 an hour for PhD software engineers and up to $17 for its AI evaluation specialist role.
- Project phase. Outlier can pay lower rates during onboarding and overtime phases, and some projects add incentive payments.
- Hours and term. Mercor's Spain physician listing expected about 21 hours a week, and its projects can be extended, shortened or ended early. xAI tutor contracts run six months.
- Review layer. A quality lead who writes rubrics and reviews other experts sits in its own tier. Second Talent prices that lead at $6,500 or more a month for domain experts and $4,000 or more for a multilingual quality owner.
Outlier states the pricing factors on one of its own job posts, which also shows how low a non-US rate can sit:
"Currently, pay rates for core project work by Video Content Description experts range from $9 to $16 per hour USD. Rates vary based on expertise, skills assessment, location, project need, and other factors.
For example, higher rates may be offered to PhDs."
Outlier job post for experts in Manila, Philippines, on Greenhouse, read October 28, 2026
For the per-sample costs of SFT and preference data, as opposed to hourly rates, see our guide to data annotation for LLM fine-tuning.
Rates by region: US, Europe, LatAm and Asia
Mercor's listing for finance professionals based in Spain or LatAm paid $50 to $100 an hour. It asked for two years at a hedge fund, private equity firm or investment bank. The same platform's investment banking network posts $100 to $130.
A second Mercor finance listing for bilingual Portuguese speakers paid $25 to $40 an hour for two to six or more years of experience and at least 20 hours a week.
Physicians in Europe sit closer to the US: a Spain-licensed physician listing paid $120 an hour, inside the US network's $115 to $150 band.
For Asia, the verifiable postings are language and description work rather than licensed experts. Mercor's Hindi language consultant role, located in India, paid $7 to $11 an hour for at least 10 hours a week over five weeks.
Outlier's Philippines post above pays $9 to $16.
Some programs sit outside the comparison. Handshake's fellowship requires US residence, and xAI's legal tutor hires in the US, the UK, Canada and Australia.
For country-level annotation pay below the expert tier, from Kenya to the Philippines, see our data annotation costs by country.
What a full-time domain-expert trainer costs in Asia
A full-time domain-expert trainer in Asia costs $2,500 to $6,500 or more a month on Second Talent's published rate card. At 40 hours a week that works out to about $14 to $38 an hour, our own calculation from the monthly range.
| Level | Monthly, Asia | Typical profile |
|---|---|---|
| Graduate | $2,500 to $3,500 | Strong degree in the field, first AI training project |
| Postgraduate | $3,500 to $5,000 | Master's or PhD, or several years of practice |
| Senior professional | $5,000 to $6,500 | Licensed practitioner or published researcher |
| Lead | $6,500+ | Sets rubrics and reviews other experts |
The fields covered are mathematics, physics, chemistry and biology, finance and accounting, law, and medicine.
Legal and medical trainers hold their qualifications in their home jurisdiction, so a model that must reason under US rules needs that stated in the brief.
Coding trainers, working software engineers who write and grade code, run $1,800 to $6,000 a month. RLHF specialists who rank outputs and write preference data run $1,200 to $4,500.
Our AI evaluation specialist page puts a senior evaluator in Asia at $4,000 to $6,500 a month, against a typical US equivalent of $14,000 to $20,000.
Worker pay is not the buyer's price
Prolific is the one platform in this set that prints its buyer fee. Its pricing page adds 42.8% to the pay a corporate customer sets, and 33.3% for academic and non-profit customers.
Applied to an expert paid $100 an hour, that fee brings the buyer's cost to $142.80, our calculation from Prolific's stated rate.
Prolific's floor is $8 an hour and its recommended minimum is $12, with more advised for AI annotation and coding work.
Mercor, Outlier, DataAnnotation, Alignerr and Scale AI publish what experts earn but not what labs pay them. Any markup figure built by setting one vendor's worker pay against another vendor's contract price compares two different things.
- $115 an hour floor for a board-certified physician on Mercor
- About $19,900 a month in expert pay at 40 hours a week, our calculation, before any platform margin
- Part-time, and projects can end early
- $5,000 to $6,500 a month for a licensed practitioner
- $6,500+ for a lead who sets rubrics
- Dedicated to one client, qualified in the home jurisdiction
The two sides buy different things. Platform hours suit a burst of US-licensed review. A full-time trainer suits a standing SFT, preference or eval program where the same expert calibrates against the rubric for months.
Hiring a domain-expert AI trainer through Second Talent
Second Talent shortlists pre-vetted domain-expert AI trainers from Asia within 24 hours, with $0 upfront and a 90-day replacement guarantee.
We confirm each degree or license and run a field test where candidates solve hard problems and grade flawed model answers. Contracts and payroll run through our Employer of Record service.
For code-heavy work, see coding AI trainers; for Asian-language data, multilingual AI trainers. To start, tell us the field your model needs.
FAQ
How much do domain-expert AI trainers cost in LatAm?
No platform publishes a LatAm rate card. The clearest data point is Mercor's finance listing for Spain or LatAm-based professionals at $50 to $100 an hour. Its US investment banking network tops out at $130.
Bilingual Portuguese finance work paid $25 to $40.
What is the hourly rate for data annotation?
For general work, DataAnnotation starts at $25 to $50 an hour and Prolific recommends at least $12. Expert work starts at $40 on DataAnnotation. Our platform comparison covers vendor fee models.
How do platforms vet domain experts?
Mercor asks for a resume and a short AI interview of about 20 minutes. DataAnnotation sorts experts into qualification tracks. Second Talent checks the degree or license and adds a field test and a writing sample.
What does the role involve day to day?
Writing hard prompts, worked solutions and rubrics, and grading model reasoning step by step. Our domain-expert AI trainer role guide covers credentials and career paths.
