New York Codes, Rules and Regulations
Title 10 - DEPARTMENT OF HEALTH
Chapter II - Administrative Rules and Regulations
Subchapter G - Aids Testing, Communicable Diseases and Poisoning
Part 66 - Immunizations and Communicable Diseases
Subpart 66-1 - School Immunization Requirements
Section 66-1.4 - Requirements for continued school attendance

A principal or person in charge of a school shall not permit a child to continue to attend such a school for more than 14 days unless a person in parental relation to the child has furnished the school with one of the documents specified in section 66-1.3 of this Subpart. Such 14 calendar day period may be extended to not more than 30 calendar days for an individual student who is transferring from out-of-state or from another country and can show a good faith effort to get the necessary evidence of immunization.