Southern Cross is the first New Zealand insurer to offer this benefit as part of its plans.
Gift of Knowledge, a national charity and support network for New Zealanders affected by hereditary breast and ovarian cancers, has called the new benefit a "big step forward in recognising prophylactic surgery can be life-saving".
Breast cancer is the third most common cancer in New Zealand. It claims the lives of more than 600 women each year.
The New Zealand Breast Cancer Foundation estimates a woman with a BRCA gene change will have a 50 to 85 per cent lifetime risk of developing breast cancer, and a 20 to 40 per cent risk of developing ovarian cancer.
This was compared with the general population risk of around 10 per cent for breast cancer, and 1.6 per cent for ovarian cancer.
The Ministry of Health said some women were at greater risk of breast cancer because close family members also had the disease, but most sufferers would have no relatives with the disease.
Southern Cross also announced it would be removing the $100,000 surgical treatment limit on selected plans.
Product and marketing head Chris Watney said genetic testing could identify a person's increased risk for developing a life-threatening condition, and it was changing the way people look at their health.
"If it's highly likely a condition " such as breast cancer or ovarian cancer " will develop, prophylactic surgery can be recommended as the best course of action. We want to support members in this difficult decision and give them more options."
Angelina Jolie underwent a double mastectomy in 2013 and had her ovaries removed in March last year as a preventative measure, due to the BRCA1 gene mutation linked to breast and ovarian cancer. Her mother, grandmother and aunt died of cancer.
New Zealanders with Southern Cross will be able to claim a lifetime allowance for prophylactic benefits of between $30,000 and $50,000.
