What do I say about why I left my last job? after 6 years as an insurance claims processor

I have an interview next week and I am unsure how to explain why I left my last job as an insurance claims processor. I have been trying to stay organised about it. I also do not want to seem like a risk. What do you say?

If a company has been in the news for layoffs, you can mention that. Often the interviewer already knows.