President Barack Obama's top health official is asking for an investigation into the administration's botched rollout of the online portal for insurance coverage under the new U.S. health care law.

Technical problems turned HealthCare.gov into a frustrating bottleneck for millions of consumers. It's working better now after two months of repairs.

Health and Human Services Secretary Kathleen Sebelius said in a blog post early Wednesday that she is asking the department's inspector general to investigate the contracting process, management and performance and payment issues that may have contributed to the flawed launch.

The announcement comes as Sebelius heads to Capitol Hill for another round of grilling before the House Energy and Commerce Committee.