(Bloomberg) — The price tag for healthcare.gov, the Patient Protection and Affordable Care Act website, is approaching $1 billion even as key features remain incomplete, congressional auditors said.

The budget to get the site ready for the next round of enrollments, starting in November, jumped to $840 million as of March, according to the Government Accountability Office. That's a $163 million increase since December.

Accenture Plc, the company that took over building the site that failed at its introduction this past October, is expected to be paid $175 million as of June, an $84 million increase from the estimate in January when it signed a contract. The data are part of testimony for a congressional hearing tomorrow in the Republican-led House. The GAO places blame for the rising price on poor planning and supervision of contractors who built the website for the federal health exchange.