It looks like BCBS is a no. Aetna and Kaiser are (limited?) yesses.
Just did a Google search and found these links from Nov 2014:
http://www.washingtonpost.com/blogs/federal-eye/wp/2014/11/07/federal-worker-health-plan-to-cover-sex-changes-and-transgender-care-next-year/ 🔗"Blue Cross Blue Shield, the most popular carrier within the federal network, with more than 2.6 million government enrollees last year, will not cover transgender care next year."
http://archive.federaltimes.com/article/20141106/MGMT01/311060012/Transgender-care-available-some-federal-health-plans 🔗 "Blue Cross Blue Shield, which maintains coverage for a majority of federal employees in the FEHBP, has maintained its exclusion of transgender care for 2015."
http://go.nationalpartnership.org/site/News2?abbr=daily2_&page=NewsArticle&id=46061 🔗 [Link: go.nationalpartnership.org/site/News2/]"Coverage Changes
Aetna's federal employee plan will cover gender affirmation surgery next year and be available to enrollees in all 50 states. About 121,000 federal employees were covered through Aetna last year, according to the Congressional Research Service.
Kaiser Permanente, which covered 240,000 federal employees last year, and the American Foreign Service Benefit Plan, which provides coverage for members of the American Foreign Service Protective Association, also will cover transgender care, "Federal Eye" reports.
However, Blue Cross Blue Shield, which provided coverage for more than 2.6 million federal employees last year, has not announced plans to cover such care (Hicks, "Federal Eye," Washington Post, 11/7). "