The government is due to announce what progress the NHS in England has made towards balancing its books by the end of the financial year.
Hospitals are responsible for a large part of the deficit
It will use Strategic Health Authority data for April to December to predict what the NHS's financial position will be on 31 March.
Health Secretary Patricia Hewitt has pledged the NHS as a whole will end the year without debt.
But half-yearly figures suggested a £94m shortfall in NHS funds.
That compares with a predicted £18m surplus three months in to the financial year.
Hospitals and primary care trusts, which are local health bodies in charge of community services such as GPs, accumulate the biggest debts.
But their financial problems are likely to be offset by funds from strategic health authorities' training and public health budgets.
Hospitals and PCTs finished the 2005-06 financial year nearly £1.07bn in deficit, leaving the NHS in the red by more than £500m once surpluses made elsewhere were taken into account.
That deficit was paid off by cuts made to this year's budget.
Many NHS bodies are having to tighten their belts as the end of the financial year approaches.
A BBC poll this month found a quarter of primary care trusts in England are asking patients to wait longer for hospital care to bring down NHS deficits.
Some are taking measures such as taking out light bulbs to cut electricity bills and bans on ordering new stationery before the start of the new financial year.