There will be two major releases of the Practice Test as follows:
A Performance based Assessment (PBA) component, administered after approximately 75% of the school year, and
An End of Year assessment (EOY) component, administered after approximately 90% of the school year. The exact dates are not published yet.

Below is more details on the two releases of PARCC:

Performance based Assessment

English Language Arts/Literacy: Grades 3-11 Performance Based tests
Mathematics: Grades 3-8 Performance Based tests in Algebra I, Algebra II, and Geometry
At each grade level the Performance Based Assessment component will require five sessions – three sessions for ELA/Literacy and two sessions for Mathematics.

End of Year Assessment

English Language Arts/Literacy: Grades 3-11 End of Year tests
Mathematics: Grades 3-8, Algebra I and Geometry End of Year tests
The End of Year component at each grade level will require four sessions – two sessions for ELA/Literacy and two
sessions for Mathematics.