Student Health Insurance with Pre-existing coverage

In health insurance parlance a pre-existing condition is a health ailment that already exists whether or not it has been diagnosed and being treated for before the customer purchases health insurance plan.
A pre-existing condition could be any condition as common as and as serious as heart disease, high blood pressure, cancer, type 2 diabetes and asthma. These are some chronic disorders that affect large part of the population.
One of the rules, as per the Affordable Care Act (popularly known as Obamacare for students) that got signed into law in March 2010, is the elimination of the pre-existing condition requirements imposed by health plans.
Insurers use "look back" period or 'Exclusion Period' or 'Waiting Period' to determine if the condition is considered pre-existing or not. The "look back" period or the "Exclusion Period' varies from one state to another depending on the policy and the concerned state insurance regulations and can range from 6 to 18 months.

For Instance: Mary a 48 year old woman is already diagnosed with Type 2 Diabetes. She is looking for a J1 visa health insurance plan as she is a visiting J1 scholar planning to join a University in US. The plan that she finally decides to buy has a 6 month waiting period or exclusion period by which she will not be covered by the insurance for any claims that occur in the first immediate 6 months of the effective start date of the insurance plan for her diabetes related expense. After the first 6 months of the policy effective date, she will be covered for any of the claims made for any treatment related to her diabetes condition.