N.Y. Comp. Codes R. & Regs. tit. 10, § 66-2.2 – Requirements for attendance at an institution.

(a) No institution shall permit any student to attend such institution unless the student has furnished to the institution the documentation in subdivision (b), (c), (d), or (e) of this section.
(b) A certificate of immunization that shows the student has:
1. (1) either:
  1. (i) received two doses of live measles virus vaccine, the first dose administered after the age of 12 months and the second dose administered more than 30 days after the first dose but after 15 months of age; or
  2. (ii) been diagnosed by a physician as having had measles disease; or
  3. (iii) demonstrated serological evidence of measles antibodies; or
  4. (iv) if the student is unable to provide a certificate of immunization that satisfies the requirements in subparagraph (i), (ii) or (iii) of this paragraph, documentation that proves the student attended primary or secondary school in the United States after 1980 will be sufficient proof that the student received one dose of live measles virus vaccine. If such documentation is provided, then the student must also provide a certificate of immunization that documents a dose of measles vaccine was administered within one year prior to attendance at the post-secondary institution; and
2. (2) either:
  1. (i) received a single dose of live rubella virus vaccine administered after the age of 12 months; or
  2. (ii) demonstrated serological evidence of rubella antibodies; and
3. (3) either:
  1. (i) received a single dose of live mumps virus vaccine administered after the age of 12 months; or
  2. (ii) been diagnosed by a physician as having had mumps disease; or
  3. (iii) demonstrated serological evidence of mumps antibodies:
(c) A certificate of immunization that shows the student is in the process of completing the requirements of subdivision (b) of this section and:
1. (1) has received at least one dose of live measles virus vaccine as required in subdivision (b); and
2. (2) has complied with the requirements in subdivision (b) of this section for mumps and rubella; and
3. (3) has an appointment to return to a health practitioner for the remainder of the immunizations specified in subdivision (b), if this appointment is scheduled no more than 90 days since administration of the first dose of measles virus vaccine.
(d) If any licensed physician, licensed midwife (caring for a pregnant student), or nurse practitioner certifies in writing that one or more of the required immunizations may be detrimental to the student's health or is otherwise medically contraindicated, the requirements of subdivisions (b) and (c) of this section shall be waived until such immunization is determined no longer to be detrimental to the student's health or otherwise medically contraindicated. This statement must specify those immunizations which may be detrimental and the length of time they may be detrimental.
(e) A written and signed statement from the student or in the event that the student is a minor, from their parent or guardian, that they hold sincere and genuine religious beliefs which prohibit immunization of the student. When a religious exemption is claimed, the institution may require supporting documents.