It depends!
For employment – the SEI Endorsement is required for a core academic teacher of English learners within one year of the date of assignment. This applies for ANY license type (including waivers!).
For licensure – The SEI Endorsement is required for Initial licensure as a core academic teacher and for all administrator Initial license. The SEI Endorsement is NOT required to apply to extend an Emergency license.
Educators can qualify for the SEI Endorsement by completing an SEI Endorsement course, a passing score on the SEI MTEL, holding an ESL license or other coursework/credential that is accepted by DESE.