Codeless/Semi-Codeless GPS Access Commitments

These documents describe U.S. government commitments to support codeless/semi-codeless civilian access to the current P(Y) signals and the transition to the modernized L2C and L5 signals. This transition will not affect users of consumer GPS devices that use only the basic civil signal (L1 C/A).

Some links on this page lead to content in the Portable Document Format (PDF) and may require you to install PDF software. Get software

Federal Register Notice: Preservation of Continuity for Semi-Codeless GPS Applications

This public notice from Sep 2008 commits the U.S. government to supporting codeless/semi-codeless access to the GPS P(Y) signals until Dec 31, 2020. Users of codeless/semi-codeless GPS receivers are advised to transition to new user equipment utilizing the modernized GPS signals (L2C, L5).

View notice

Prior to issuing this notice, the government collected public comments on the idea of the 2020 sunset date for codeless/semi-codeless GPS access. View comments at

arrowReturn to top of page


Public Letter from Air Force Space Command

In Dec 2009, General C. Robert Kehler, Commander, Air Force Space Command, in a letter addressed to the Honorable James R. Schlesinger, confirmed the Air Force's intent to comply with the 2008 Federal Register notice and to document a commitment to phase stability for the new civil GPS signals.

View letter
(250 KB PDF)

arrowReturn to top of page


This Interface Specification defines the GPS signals used for codeless/semi-codeless GPS access. It also defines the L2C signal designed to supplant the future need for legacy codeless/semi-codeless techniques. Revision E of the document, dated Jun 8, 2010, and all subsequent editions include new language establishing a baseline phase relationship for the L2C signal. This link leads to the IS-GPS-200 section of the Interface Control Documents page. Go there

arrowReturn to top of page

Take Action: