Exhibit 21.1
SUBSIDIARIES OF NCS MULTISTAGE HOLDINGS, INC.
| Subsidiary | State or Other Jurisdiction of Formation |
| Pioneer Intermediate, Inc. | Delaware |
| Pioneer Investment, Inc. | Delaware |
| Pioneer NCS Energy Holdco, LLC | Texas |
| NCS Multistage, LLC | Texas |
| STS Logistics and Analytics, LLC | Oklahoma |
| STS Holdings, Inc. | Nevada |
| STS Tracer Services, Ltd. | Canada |
| NCS Multistage Norge | Norway |
| Repeat Precision, LLC | Texas |
| RJ Machine Mexico, S. de R.L. de C.V. | Mexico |
| NCS Multistage Global Services, LLC | Texas |
| NCS Multistage Global Services, LLC (UK) | United Kingdom |
| NCS International, LLC | Texas |
| NCS Multistage Argentina S.R.L. | Argentina |
| NCS International 2, LLC | Texas |
| NCS Multistage Inc. | Canada |