N.Y. Comp. Codes R. & Regs. tit. 12, § 355.9
(a) As used in Part 380 of this Title:
(16) Serious health condition means an illness, injury, impairment, or physical or mental condition that involves: inpatient care in a hospital, hospice, or residential health care facility; or continuing treatment or continuing supervision by a health care provider. Serious health condition also means a COVID-19 diagnosis by a health care provider.
(i) As used in this Title, continuing treatment or continuing supervision by a health care provider means one or more of the following:
(a) a period of more than three consecutive, full days during which a family member is unable to work, attend school, perform regular daily activities, or is otherwise incapacitated due to illness, injury, impairment, or physical or mental conditions, and any subsequent treatment or period of incapacity relating to the same condition, that also involves:
(b) any period during which a family member is unable to work, attend school, perform regular daily activities, or is otherwise incapacitated due to a chronic serious health condition. A chronic serious health condition is one which:
(d) a period during which a family member is unable to work, attend school, perform regular daily activities, or is otherwise incapacitated because he or she is receiving treatment (including any period of recovery therefrom) by a health care provider for: