The Australian Paramedics Association says it will ban staff movements and undertaking scheduled non-urgent transfers on Tuesday.
Paramedics will only work out of the stations they start their shifts at and won't transfer to other stations throughout the day to fill roster gaps.
Those in the north of the state are being excluded from industrial action due to the flood recovery effort.
The union's NSW assistant secretary Alan O'Riordan told AAP on Monday the escalation of industrial action, beyond the chalked messages that have adorned NSW ambulances for several months, was necessary because "the government just keeps ignoring us".
He said there has been no engagement from the government and that was the same level of respect most other healthcare workers were being shown throughout the pandemic.
The union wants more paramedics and boosted pay and held a similar action in February.
Mr O'Riordan said 1500 extra paramedics would help replace those who are leaving the workforce due to burnout and other factors, but even more would be required to meet the full requirements of the state's more than 8 million people.
More specialist paramedics are also needed in the regions and paramedics are looking for a "meaningful pay increase", which Mr O'Riordan said would be a three to five per cent raise at minimum.
Mr O'Riordan said a good response from the government on Tuesday would be to simply acknowledge there is a problem in the paramedic workforce and begin meeting with workers, so taxpayers get the ambulance service they deserve and pay for.
But he expects "probably very, very little" will actually come out of the action and "we will just be ignored yet again".
Nurses are planning to walk off the job for 24 hours on Thursday to hold public rallies calling for pay rises and improved nurse to patient ratios.
The office of Health Minister Brad Hazzard has been contacted for comment.