Customers who buy an iPhone 4 after Sept. 30 won’t able to request a free case through Apple’s case program, Apple announced today (http://www.apple.com/iphone/case-program/). However, they will be able to contact AppleCare to request a free Bumper.

“We now know that the iPhone 4 antenna attenuation issue is even smaller than we originally thought,” says Apple. “A small percentage of iPhone 4 users need a case, and we want to continue providing them a Bumper case for free.”

For everyone else, Apple is discontinuing the free case program on all iPhone 4s sold after Sept. 30. The company is also returning to its normal returns policy for all iPhone 4s sold after that date. Users experiencing antenna issues should call AppleCare to request a free Bumper case.