Brokers have responded with enthusiasm to PruHealth's promise not to penalise policyholders with high premiums if they are living a healthy lifestyle, according to the private medical insurer.
The new underwriting approach, Vitality Underwriting, is designed to broaden the policy's relevance to new and existing clients.
Dave Priestley, sales director at PruHealth, said: "In our roadshows brokers showed real excitement in our new Vitality Underwriting, because they see they will be able to sell PMI to those who wouldn't normally be covered fairly in a PMI policy."
PruHealth was the first to develop a health incentive PMI scheme in 2004, which resulted in reduced premiums if customers took steps to become healthier.
It has since seen interest from around 650 brokers with a third of those placing business.
"We are seeing what you would call more generalised brokers becoming more involved in PMI, which has benefits all round," said Priestley.
PruHealth now covers 50,000 customers with its membership doubling in the past six months. "What is crucial is that we are actually growing in the market - a third of our individual customers are new to PMI," said Shaun Matisonn, PruHealth chief executive.