The Southern District Health Board has "doubtful debts" of $800,000 this year, much of it related to unrecoverable costs for medical treatment provided to overseas patients.
Chief financial officer Robert Mackway-Jones said last year the amount was $317,000.
The board budgeted for $231,000 in this area but expects to end the year with $833,000 worth of debts where recovery is unlikely.
Assessments had to be made in each case to ensure the cost of pursuing a debt was not more than the amount likely to be recovered.
At least one of the amounts involved in this year's debts is more than $100,000.
Such high amounts were where the person involved had hospital treatment involving intensive care.
Mr Mackway-Jones said the Ministry of Health assessed boards' levels of debt write-offs and in those areas such as Auckland where they could be as high as $3 million, some special funding was allocated.
Some non-residential debts were as a result of people coming into the country without declaring medical conditions which then needed treatment once they were here.
Clinicians would face an ethical dilemma if they were to refuse treatment to someone who was seriously ill.
Non-residents booking in for elective surgery was a different matter - "that's not going to happen", he said.
It was pleasing to note that some of the immigrant work schemes now required compulsory health insurance, but there were always exclusions to such policies.
Last financial year the two boards which make up the new Southern board received about $1.159 million for the care of non-resident patients.
