No, group health insurance policy is usually not subject to waiting period be it for any Pre-Existing Disease condition (PED) e.g.: Diabetes, Blood Pressure, Heart disease, etc., or Specified Diseases e.g.:  Sinus, Knee replacement, Cataract, etc unlike retail insurance. However, this might change if your organisation has opted for a waiting period. For more clarification, you can view your policy handguide.