Lakes District Health Board acting chief operations officer Julie Eilers said elective surgery cases and most outpatient clinics were being rescheduled for the two days of the strike.
However, the health board said it was unable at this stage to provide the Rotorua Daily Post details of how many people would be affected with appointments or outpatients being rescheduled, or when they might be rescheduled to.
Ms Eilers said staff were focused on trying to reduce the number of patients in the hospital by the end of this week.
She said the reduction of non-urgent services was being rolled out to ensure the health board's 90 or so senior doctors could focus on those most in need during the strike.
While all elective procedures are being postponed, two theatres will be staffed to allow for acute surgery to proceed, she said.
Only urgent cases would be dealt with at the emergency department at Rotorua Hospital during the strike. Taupo Hospital does not employ junior doctors so is not expecting to be greatly affected by the strike.
"People should ensure they are up to date with their prescriptions and other requirements, and if they get into difficulty, they should make their GP or Lakes PrimeCare their first port of call," said Ms Eilers.
Ms Eilers said the contingency planning focused on ensuring the continuing provision of essential emergency services including acute surgery, emergency department care, intensive care and maternity care.
Whakatane Hospital is also preparing to reduce elective surgery and some outpatient appointments during the strike.