Austin has apologized for the way he handed the matter, including to Biden himself, but his appearance before the Republican-led House of Representatives Armed Services Committee at 10 a.m. (1500 GMT) will be the first time lawmakers will directly question him.
The hearing is expected to be one of the most contentious and personal that Austin, a retired four-star general, has faced in his career.
"It's totally unacceptable that it took over 3 days to inform the President that the Secretary of Defense was in the hospital and not in control of the Pentagon," Representative Mike Rogers, the committee's chairman, will say at the hearing, according to prepared remarks.
"Wars were raging in Ukraine and Israel, our ships were under fire in the Red Sea, and our bases were bracing for attack in Iraq and Syria. But the Commander in Chief did not know that his Secretary of Defense was out of action."
Instead of disclosing his health situation, Austin opted to keep secret his initial prostate cancer surgery in December as well as a subsequent January hospitalization for post-surgical complications that landed him in the intensive care unit.
Still, the Pentagon released the results from an internal 30-day review on Monday that effectively absolved itself of any wrongdoing. It concluded that "nothing examined during this review demonstrated any indication of ill intent or an attempt to obfuscate."
Rogers is expected to criticize the report for failing to provide real answers for who knew what, when and who failed to perform their basic duties.
"We were led to believe your 30-day internal review would shed light on the matter," Rogers will say, according to the prepared remarks.
"But it includes no explanation of why the President and his staff were left in the dark. It makes no recommendations to improve communication with the White House. And unsurprisingly, it holds no one accountable."
At a rare press briefing earlier in February, Austin, who is intensely private, took responsibility for failing to tell Biden and senior staff about his prostate cancer diagnosis ahead of time, adding that the health scare was a "gut punch" that had shaken him.
But both Republican and Democratic lawmakers criticized Austin for failing to disclose the cancer diagnosis and subsequent hospitalizations. Some prominent Republicans, including former President Donald Trump, called for Austin to be removed from his job.
(Reporting by Phil Stewart and Idrees Ali; Editing by Alistair Bell)
