Just over 106,000 people picked health plans in the first month of open enrollment through the state and federal insurance marketplaces established by the Affordable Care Act, President Obama's health secretary said Wednesday, a fraction of the administration's initial estimate for enrollment during that period. Only about a fourth of the new enrollees — 26,794 — signed up through HealthCare.gov, the problem-plagued federal exchange, according to figures released by the Centers for Medicare and Medicaid Services. A much larger number, 76,319, signed up through the 14 state-run marketplaces.