45% of the population - or 2.17 million people - held a private health insurance policy at the end of last year, according to figures from the Health Insurance Authority.
That represented an increase of 22,000 on the figure in 2016.
Premium income came in at €2.66 billion - up from €2.53 billion in the previous year.
The average amount paid for a health insurance premium for in-patient cover in 2017 was €1,220, compared to €1,177 in 2016.
That was an increase of 3.7% and was up significantly on the 0.3% premium increase in 2016 over the previous year.
After a fall off in the numbers insured in the years following the downturn, there was an upsurge in recent years following the introduction of lifetime community rating.
This was the principle whereby individuals taking out health insurance for the first time would pay a 2% loading for every year over the age of 34 when they first enter the market.
VHI Healthcare's market share was 50%, while Laya Healthcare has 26% market, share and Irish Life Health had 20%.
"The private health insurance market has continued its consistent growth, with the market experiencing its third straight year of increase in in the number of people insured," Health Insurance Authority CEO, Don Gallagher said.
"Reduction in net emigration, growth in employment, introduction of young adult rates, and lifetime community rating, have all contributed to the increase in the insured population, which now stands at 2.17 million - representing 45% of the population. Furthermore, a more buoyant economy and increased disposable incomes, have also undoubtedly helped facilitate the year-on-year increase in the total number insured on in-patient plans."