Passport pages deadline is December 31, 2015

If you are running out of pages in your passport for Visas and entry/exit stamps, apply before the end of the year for additional 24 blank pages - and you will need to surrender your Passport with other require information. It's $82 fee and Form DS-4085.
Passport renewals now offer a 52-page (43 blank) option at no additional charge while the standard 28-page (17 blank) remains available.  Form DS-82 is used for renewal.  Of course visit travel.state.gov for official details - including latest update on processing time which can be weeks.
Another good link is passport.info.com