Long Islanders with underlying health conditions can now sign up to get vaccinated for COVID-19.

The state's "Am I Eligible?" screening tool was updated Sunday morning and those with pre-existing conditions and comorbidities can sign up to be vaccinated at distributed centers across Nassau and Suffolk counties.

The new appointments will be released on a rolling basis.

The eligibility applies to people conditions like cancer, obesity, heart and neurological conditions, pregnancy and more.

Those who apply will need to submit proof of their condition in the form of a doctor's letter, medical evidence of a comorbidity or a signed certification.

News 12 is told that the state's website was overwhelmed Sunday.

Officials say as time goes by, vaccination sites will be able to administer more doses. According to the state, the supply coming from the federal government will increase by more than 20% over the next three weeks.