Amazon Mechanical Turk shutdown: questions and answers

Facts checked against mturk.com and AWS documentation on 2026-10-02. We update this page when the notices change.

Amazon Mechanical Turk (MTurk) is closed. It stopped accepting new requesters on 2026-07-30 and closed permanently on 2026-09-30. A few deadlines still run after the closure, and the change reaches into two AWS services that many teams used without ever opening the MTurk website: SageMaker Ground Truth and Amazon Augmented AI (A2I).

This page answers the common questions, using dates only from the official notices. For step-by-step migration help, read the Ground Truth and A2I migration guide after this one.

The dates in one place

| Date | What happens | |---|---| | 2026-07-30 | MTurk stopped accepting new requesters. | | 2026-09-30 | MTurk closed permanently. HIT submission ended. The MTurk worker type was removed from Ground Truth and A2I. | | Until 2026-10-30 | Requesters can approve or reject submitted HITs and award bonuses. Untouched HITs are auto-approved. | | Until 2027-01-28 | Transaction history stays available. |

Is MTurk really closed, or only closed to new customers?

Closed. The mturk.com help page says "Amazon Mechanical Turk is permanently closed as of September 30, 2026." The earlier step, on 2026-07-30, only stopped new requesters from signing up. The 2026-09-30 step ended the service for everyone.

I am a requester. What do I still need to do?

Three things before 2026-10-30, in this order:

1. Approve or reject submitted HITs. MTurk's FAQ gives requesters 30 days from the closure to act. HITs left untouched are auto-approved, so if you need to reject poor work, you have to do it yourself before the deadline.
2. Pay any bonuses. Bonuses for completed HITs can be awarded until the same date.
3. Check your payment information. MTurk asks requesters to verify payment details in the Requester Portal so refunds are processed. After 2026-10-30, it directs payment changes to customer service.

Then, before 2027-01-28, download your transaction history for finance and audit records.

What happened to HITs that were still open?

MTurk's FAQ says all remaining unsubmitted HITs expired automatically when HIT submission closed on 2026-09-30, and that requesters are not charged for incomplete HITs. Submitted HITs follow the approval rule above.

What happens to my prepaid balance?

MTurk's FAQ says to expect a full refund of a prepaid requester balance within 30 days of the closure, and to contact MTurk customer service if it does not arrive in that time. Final charges appear on your AWS bill in the billing cycles that follow the closure.

Did SageMaker Ground Truth and Amazon A2I close too?

No. What changed is narrower. The Amazon Mechanical Turk worker type is no longer available for labeling jobs or human review workflows as of 2026-09-30. Private workforces and vendor workforces still work in both services.

One more fact matters if you are planning ahead. As of 2026-10-02, AWS's documentation states that both Ground Truth and A2I are "no longer open to new customers," that existing customers can continue to use them as normal, and that AWS does not plan to add new features. If your account already uses them, you can keep going. If you are starting fresh, plan around that.

How do I know if my pipeline used the MTurk workforce?

Search for the public workforce ARN. AWS documents it as arn:aws:sagemaker:<region>:394669845002:workteam/public-crowd/default, so searching for public-crowd/default finds it in any Region. Look in:

• labeling job definitions, and the scripts or notebooks that create them
• A2I human review workflows (flow definitions)
• infrastructure code such as CloudFormation, CDK or Terraform
• code that sets the FreeOfPersonallyIdentifiableInformation content classifier, which AWS required before it would send an A2I task to MTurk

Every hit is a job or workflow that now needs a different workforce.

What are the replacement options?

For business and machine learning tasks there are four realistic paths:

• Your own staff as a private workforce. Full control. You also take on hiring, training and review.
• A managed team as a private workforce. A vendor's people sign in to your labeling portal. You keep access control, and the vendor runs training and QA. The A2I private workforce set-up guide covers the steps.
• A vendor workforce from AWS Marketplace. You subscribe through your AWS account. AWS's documentation tells you to check each vendor's security and compliance details before you send sensitive data.
• Move the task out of AWS labeling tools. If Ground Truth or A2I was only there to reach MTurk, a team can work directly in your spreadsheet, admin panel or labeling tool.

What should academic researchers use?

Recruiting participants for surveys and studies is a different job from labeling or review. Prolific and CloudResearch are built for it, with participant pools and screening tools.

Can I reuse my HIT instructions?

Yes, as a starting point. Instructions written for anonymous workers tend to be short and defensive. When you move to a known team, add finished examples, the edge cases you used to reject, and a way for people to ask questions. How to write annotation guidelines covers this in detail.

I worked on MTurk. What do I need to do?

MTurk's FAQ asks workers to verify payment preferences in the Worker Portal by 2026-10-30. Payments follow your existing schedule, and completed, approved HITs are paid in the normal disbursement. After 2026-10-30, payment changes go through MTurk customer service.

A one-page checklist

• [ ] Approve or reject every submitted HIT (by 2026-10-30)
• [ ] Pay any bonuses (by 2026-10-30)
• [ ] Verify requester payment information (by 2026-10-30)
• [ ] Watch for the prepaid balance refund
• [ ] Download transaction history (by 2027-01-28)
• [ ] Search code and infrastructure for public-crowd/default
• [ ] Choose a workforce for each affected job or workflow
• [ ] Recreate A2I human review workflows with the new work team
• [ ] Run a test batch against known answers before moving full volume

Sources

• Amazon Mechanical Turk closure FAQs, https://www.mturk.com/help, checked 2026-10-02
• AWS SageMaker Developer Guide, "Workforces" and "Using the Amazon Mechanical Turk Workforce", https://docs.aws.amazon.com/sagemaker/latest/dg/sms-workforce-management.html, checked 2026-10-02
• AWS SageMaker Developer Guide, availability notices on the Ground Truth and A2I overview pages, https://docs.aws.amazon.com/sagemaker/latest/dg/sms.html and https://docs.aws.amazon.com/sagemaker/latest/dg/a2i-use-augmented-ai-a2i-human-review-loops.html, checked 2026-10-02

Disclosure: we run Deepen AI Services, a managed team that can join a Ground Truth or A2I private workforce for business and data tasks.