A senior Medicaid official broke with his own department Wednesday and came out publicly against the GOP’s bill to repeal and replace the Affordable Care Act.

Andrey Ostrovsky, the chief medical officer for the Center for Medicaid and CHIP Services (CMCS), announced in a Twitter post that he was opposed to the Republican bill pending in the House. CMCS is a division within the Department of Health and Human Services. HHS Secretary Tom Price, a former Republican congressman, is the Trump administration’s point person on Obamacare repeal and replace.

“Despite political messaging from others at HHS, I align with the experts from [American Academy of Family Physicians, American Academy of Pediatrics and American Medical Association] in opposition to #AHCA,” Andrey Ostrovsky, chief medical officer for The Center for Medicaid and CHIP Services (CMCS), wrote on Twitter.

Despite political messaging from others at HHS, I align with the experts from @aafp @AmerAcadPeds @AmerMedicalAssn in opposition to #AHCA — Andrey Ostrovsky, MD (@AndreyOstrovsky) March 9, 2017

Ostrovsky, an Obama appointee who assumed his role in September 2016, joins associations representing hospitals, doctors, seniors and insurers who have criticized the bill this week. Like Democrats and moderate conservatives who oppose the legislation, those groups say the proposal provides low-income and aging Americans with much fewer protections than they had under Obamacare.

The AHCA phases out Obamacare’s Medicaid expansion and caps Medicaid spending provided to states by the federal government.

Andy Slavitt, who ran the Centers for Medicare & Medicaid services under Obama and has heavily criticized the GOP bill, praised Ostrovsky as a “hero” on Twitter.

We should have a ton of admiration for @AndreyOstrovsky and what he did tonight. In my book he’s a hero. In his he just serves the public. https://t.co/f3UKTq6P1E — Andy Slavitt (@ASlavitt) March 9, 2017

Ostrovsky thanked him for his support, noting that the AHCA fails to offer “rigor of evidence” for the drastic changes it makes to the Medicaid program.