Friends Life has revealed it paid out over £90m in group protection claims to over 2,300 people during 2013.
The insurer revealed its claim pay-out rate percentages for the first time following industry body GRID's publication of claim rates.
Friends Life paid out 100% of group life claims, 95% of group income protection claims and 86% of group critical illness claims.
For group income protection the main causes of claims were mental health, cancer and musculoskeletal conditions.
For group critical illness, cancer and heart attacks were the main causes.
Around 5% of income protection claims were declined, mainly because the definition of disability wasn't met.
Additionally of all CI claims submitted in 2013, 7% were declined due to the definition not being met and a further 7% declined due to the associated conditions and pre-existing conditions exclusion.
David Williams, director of group protection at Friends Life, said the publication was about transparency.
He said: "You do get some questions although not as much as on the individual protection side, but we thought it was important to show transparency. It also shows how many people we support.
"We're prepared to be transparent about what we do but also this the value that we bring to employers and employees. We followed the GRID definitions and thought once the data from GRID was released, it was appropriate to share our data."