The Department of State announced that the full names of an applicant's parent(s) must be listed on all certified birth certificates in order for the certificates to be considered primary evidence of U.S. citizenship. This new documentary requirement applies to all passport applicants, regardless of age. Certified birth certificates missing this information will not be acceptable as evidence of citizenship. This does not affect applications that were submitted or accepted before April 1, 2011.

The announcement is available here. Links to vital records offices state-by-state are available here.