Alternate assessments have been implemented in States for over 15 years.  During this time, the nature and purpose of alternate assessments has changed, including participation.  In 2003 the Elementary and Secondary Education Act (ESEA) placed a 1% cap on the percentage of the total tested student population that could count as proficient on the alternate assessment, based on alternate achievement standards. This was not a cap on participation in the assessment.

In 2015, with the reauthorization of ESEA as the Every Student Succeeds Act (ESSA), the requirement changed for the alternate assessment based on alternate academic achievement standards--AA-AAAS.  ESSA reaffirmed that the alternate assessment is an appropriate assessment for students with the most significant cognitive disabilities to demonstrate their knowledge and skills, but rather than placing a limit on the number of proficiency scores for the alternate assessment, ESSA places a 1% threshold, or limit,  on participation in the assessment. 
Local Educational Agencies (LEAs) no longer reallocate proficient scores that exceed the 1% cap, as that cap no longer exists in regulation. Rather, LEAs must ensure that IEP teams are adhering to the PASA Eligibility Criteria and that 1% of the test population is participating in the alternate assessment.  The Bureau of Special Education (BSE) has oversight of the PASA and will analyze participation data for each LEA.  LEAs have been directed to complete and submit a 1.0 Threshold Participation Justification to the BSE if anticipating exceeding the 1% participation threshold for the upcoming school year.  The waiver does not grant approval to exceed the 1% participation threshold. The State and LEA must make this information available to the public.  The State will identify the names of the LEAs who anticipate assessing more than 1.0 percent of students with disabilities on the alternate assessment.

Resources available on the 1% participation cap and ESSA are available.