Final answer:
All Institutional Special Needs Plans (IE-SNP) enrollments require a Provider Attestation Form completed by a healthcare provider to confirm member eligibility.
Step-by-step explanation:
The additional enrollment document required for all Institutional Special Needs Plans (IE-SNP) enrollments is a Provider Attestation Form. This form must be completed by the attending healthcare provider to confirm that the enrolling member does indeed meet the eligibility criteria for a Special Needs Plan (SNP) targeted at residents of institutions like nursing homes, or eligible for nursing home care. This form serves as a critical piece of documentation ensuring that enrollees have the specific health care needs that align with the services provided by an IE-SNP.