I have several paid up credit cards I want to close out, how will this affect my credit score?

I am working on paying off my credit cards because I am planning to retire in 3 to 5 years. Is it ok to close out these paid up cards all at one time or does it matter?

Your score is based in part on the percentage of your available credit you have used. Closing paid off cards reduces the amount of credit you have available to you and will therefore lower your credit score some. But that may not matter if your other balances are low (and you are still using less than 10% of your remaining available credit) and you won’t be applying for a mortgage anytime soon.