Organizations that received the latest round of health law navigator grants say last week's letter from House Republicans could have a chilling effect on efforts to hire and train outreach workers to sign up Americans for health insurance by Oct. 1, the opening day for new online insurance marketplaces. The letters were signed by 15 Republican members of the House Energy and Commerce Committee and requested that the organizations provide extensive new documents about their participation in the program and schedule a congressional briefing by Sept. 13.