It can vary. There is a fee for Form I-821 if you are registering for TPS for the first time. There is no fee for Form I-821 if you are re-registering for TPS.
Fees are also dependent if you are applying for work permit authorization (or EAD card) under TPS and if you need to pay biometric fees (not everyone does).
You can reference this chart via the USCIS TPS website:
| The Applicant Is | Applicant's Age | I-821 Fee | Biometric Services | I-765 Fee | Total |
|---|---|---|---|---|---|
| Submitting their initial TPS application and requesting an EAD | Younger than 14 | $50 | $0 | $0 | $50 |
| 14-65 years old | $50 | $85 | $410 | $545 | |
| 66 and older | $50 | $85 | $0 | $135 | |
| Submitting their initial TPS application and not requesting an EAD | Younger than 14 | $50 | $0 | N/A | $50 |
| 14 and older | $50 | $85 | N/A | $135 | |
| Re-registering for TPS and requesting an EAD | Younger than 14 | $0 | $0 | $410 | $410 |
| 14 and older | $0 | $85 | $410 | $495 | |
| Re-registering for TPS and not requesting an EAD | Younger than 14 | $0 | $0 | N/A | $0 |
| 14 and older | $0 | $85 | N/A | $85 |
If you are still unsure, you can use the USCIS Fee Calculator to help determine your fee.