http://www.health.gov.on.ca/en/public/publications/ohip/travel.aspx
How long do I have to stay in Ontario immediately after I establish residency in Ontario?
Generally, if you have moved to Ontario from outside Canada, or if you have moved from another Canadian province or territory and were not insured by that province or territory's public health insurance plan, you must be present for 153 days in the first 183 days immediately following the date you establish residency in Ontario (i.e. you cannot be absent for more than 30 days during the first 6 months of residency in Ontario).
How long do I have to stay in Ontario immediately after I establish residency in Ontario?
Generally, if you have moved to Ontario from outside Canada, or if you have moved from another Canadian province or territory and were not insured by that province or territory's public health insurance plan, you must be present for 153 days in the first 183 days immediately following the date you establish residency in Ontario (i.e. you cannot be absent for more than 30 days during the first 6 months of residency in Ontario).