As stated in the link http://www.apple.com/support/iphone/service/faq
Apple's Limited Warranty for iPhone excludes coverage for damage resulting from accident, disassembly, unauthorized service and unauthorized modifications. Please review the warranty for further details.
An iPhone that is ineligible for warranty service may be eligible for Out-of-Warranty (OOW) Service. For example, an iPhone that has failed due to damage or liquid damage is ineligible for warranty service but eligible for OOW service. However, certain damage is ineligible for OOW service, including catastrophic damage, such as the device separating into multiple pieces, and inoperability caused by unauthorized modifications. Please see Apple's Repair Terms And Conditions for further details. Refer to this article to check if the Liquid Contact indicator on your product has been triggered.
If your iPhone is not eligible for warranty service, you may wish to contact your carrier for other options.