Hospital managers have called for greater transparency about how the 2009-10 tariff will be affected by other cost and payment changes.
NHS Confederation policy director Nigel Edwards said the Department of Health's response to trusts reporting problems was typically that the trusts had not fully understood how the new system worked.
"There should be transparency. You shouldn't need a doctorate in quantum mechanics to understand this stuff," Mr Edwards said.
Alongside the new tariff from April, trusts face a massive hike in clinical negligence insurance costs and changes to the way they are compensated for patient transport.
The so-called market forces factor, which compensates trusts for unavoidable extra costs by supplementing the tariff price they get, will also change.
Winners and Losers
From April a new formula will calculate how much extra - if any - each trust gets. The biggest losers include major inner London teaching trusts such as King's College and Barts and the London, which will lose a net average 1.7 per cent for each procedure.
The biggest winners include trusts with a history of deficits, such as Royal Cornwall Hospital and Queen Mary's Sidcup, which will gain up to a net 2.5 per cent.
Trusts have been shocked by the 53 per cent increase in the premiums charged by the NHS Litigation Authority to cover clinical negligence claims for 2009-10. Trusts say this is not adequately reflected in the 1.7 per cent increase to the tariff.
Authority chief executive Steve Walker told HSJ: "We told the [DH] tariff team what our requirement was and they say they took it into account, which isn't the same as saying they translated it directly."