Bright Grey paid out 91% of critical illness (CI) claims in the last six months of 2011.
Just 2% of claims were declined for non-disclosure, with the average payout being £82,000.
In the first half of the year the provider paid 90% of claims with a 4% non-disclosure rate.
This gave an overall rate of 90% for the whole year.
Cancer remained the most common reason for a claim (55%), followed by heart attack (10%), stroke (10%) and multiple sclerosis (9%).
Nearly half (47%) of claims were made by people who were 40 or under and the youngest claimant was just 23 years old, having suffered a stroke.
Roger Edwards, proposition director at Bright Grey and its Royal London sister, Scottish Provident, said: "Over half of our claims were for cancer which might appear to be a frightening statistic.
"But the good news is that with better screening and earlier testing, more people than ever before are surviving the disease.
"For many, chemotherapy and other treatments mean taking months off work and this is where the money from a critical illness policy comes into its own - easing any financial worries so they can focus on getting better.
"One consequence of better screening is that we are seeing more people being treated for earlier forms of cancer.
"So, last year we introduced two definitions that provide additional cover for ductal carcinoma in situ, an early form of breast cancer and low grade prostate cancer," he added.
