The NHS is the top priority in Wales’ “bread and butter budget” with cash for road repairs to also be announced.
Finance Secretary Mark Drakeford said the Welsh Government would spend about £15bn in 2019-20.
Councils have warned of job losses and cuts to core services as a result of a squeeze on their funding.
Mr Drakeford said he recognised the strain they were under, but added: “Health is always the top priority for a Labour government here in Wales.”
Councils will get more money to help pay for road repairs after a severe winter and hot summer, but Mr Drakeford did not state how much.
“It will be a bread and butter budget in which I will be focused on sustaining the fabric of Welsh life during a period of real difficulty,” he told BBC Wales.
Tuesday’s draft budget will outline how much each government department will receive.
A more detailed breakdown of spending increases and cuts will not be available until 23 October.
In the ninth year of austerity and with the “looming shadow of Brexit over our economic future,” Mr Drakeford said ministers had tried to “squeeze every penny we can out of our budget and then to align it with the things that matter the most with the lives of people in Wales”.
This will be the final budget before Carwyn Jones stands down as first minister in December, with Mr Drakeford the favourite to succeed him.
It is also the first budget in which the Welsh Government has the power to vary income tax.
Labour has promised not to change the tax rates before the 2021 assembly election.
Since appointing independent AM Dafydd Elis-Thomas as a minister, the government now has a majority in the assembly and no longer needs a deal with another party to get its budget through the Senedd.
Health accounts for about half of the Welsh Government’s day-to-day spending on public services and Mr Drakeford said the NHS “matters most to people”.
The Welsh Government will receive extra funding as a result of UK government promises to boost the NHS budget in England, but precise figures have not been published.
That could be affected by the chancellor’s budget on 29 October.