Northern Ireland Health Minister Robin Swann has said the Stormont budget "will mean people will be at increased risk of harm".
Mr Swann and the Ulster Unionist Party (UUP), which he represents, voted against the budget.
The health department got £7.76bn - the largest share of day-to-day funding.
Mr Swann said a "health service that is actually ravaged by millions of pounds worth of cuts is bad for people's health".
He added that it would restrict "us in the use of new drugs, and therapies".
"We are hearing this morning about possible cancer treatments," Mr Swann told BBC Radio Ulster's Good Morning Ulster.
"Our Department of Health may not have the money to actually implement those in Northern Ireland along with others.
"Waiting list initiatives that we talked about that were a priority for the Executive, no monies for those.
"In fact, I am also having to look at money that was allocated in a Westminster settlement for waiting list initiatives to use for red flag emergencies."
Mr Swann said on Thursday that the health department had been "left in a position where we were actually receiving a 2.3% cut on what we receive and on what we spent last year".
Other parties in the Northern Ireland Executive agreed a spending plan for the financial year, with about £14.5bn for day-to-day spending and about £1.8bn for capital spending.
The largest allocation, after health, goes to the Department of Education - £2.87bn.
The Department of Justice has been allocated £1.26bn.
Mr Swann has warned that hospital waiting lists, pay settlements, GP services and domiciliary care packages will all be affected by the budget announcement.
'Incredibly serious consequences'
In a letter to Stormont's health committee, seen by BBC News NI, he said it was his duty to inform members of the "incredibly serious consequences" of the budget.
Mr Swann said the only additional targeted investment would be the £34m provided as part of the UK government package for the restoration of devolution.
He said approximately £75-80m was needed to ensure people with cancer or time-critical conditions could be treated as required.
The letter stated that while Mr Swann had previously asked for an additional £1billion to maintain services he was prepared to reduce this by £200m to bring the figure down to £800m.
Mr Swann said on Thursday he "could not stand over the implementation of cuts on this scale".
"Not only is this a budget that doesn't prioritise health, this is a budget that actually removes funding from the health service in Northern Ireland," he said.
In the previous budget, which was imposed by Northern Ireland Secretary Chris Heaton-Harris, health received baseline spending of just over £7.3bn.
BBC News NI understands the Department of Health has received an additional £500m.
While the health minister had previously asked for an extra £1bn, he had most recently proposed that he could try and work with £800m instead.
The department's allocation is therefore £300m short.
Finance Minister Caoimhe Archibald, of Sinn Féin, said it was regrettable no department got all the funding for which they bid.
She renewed her call to the UK government to review the overall public spending settlement for Northern Ireland.
Her department said the total available funding for departments rose by 6.3% from last year's opening position to £13.5bn to £14.4bn this year.
Ms Archibald said the Department of Health's allocation included £34m to tackle waiting lists.