Dr. Rachel Levine was confirmed by the Senate to serve as Biden's assistant secretary of health, making history as the first openly transgender person to be confirmed by the Senate and the highest ranking openly transgender government official.
The Senate confirmed her by a vote of 52-48.
Along with the Democrats, Levine was backed by moderate Republicans Susan Collins, R-Maine, and Lisa Murkowski, R-Alaska.
Levine -- who was serving as Pennsylvania's secretary of health, the highest ranking health official in the state -- now becomes the No. 2 at the Department of Health and Human Services, where she will serve directly under newly confirmed Secretary Xavier Becerra.
She'll join HHS as the department looks to address both the COVID-19 pandemic and the influx of immigrant children crossing the southern border.
The Senate Health, Education, Labor and Pensions committee chair, Sen. Patty Murray, praised Levine's experience on the Senate floor before the vote, highlighting her work on Pennsylvania's COVID-19 response.
"Dr. Levine has been on the front lines of this pandemic, which is why she knows firsthand what our states and communities need from the Department of Health and Human Services," Murray said.
She also highlighted the historic nature of Levine's confirmation for the transgender community.
"I've always said the people in our government should reflect the people it serves, and today we will take a new historic step toward making that a reality," Murray said.
Before taking the helm of Pennsylvania's Department of Health, Levine served as the state's physician general. She is a trained pediatrician with degrees from Harvard and Tulane University.
During her confirmation hearing last month, Levine vowed to fight for improved health care access for all.
At that hearing, she faced a line of questioning from Sen. Rand Paul, R-Ky., that mischaracterized transgender people and likened gender affirming surgeries to "genital mutilation."
Throughout his line of questioning, Paul repeatedly asked Levine if she believed minors should be able to make decisions to "amputate their breasts or amputate their genitalia."
Levine responded by pledging to meet with Paul, an eye doctor, to discuss transgender medicine.
"Transgender medicine is a very complex and nuanced field," Levine said. "We have robust research and standards of care that have been developed, and if I am fortunate enough to be confirmed as the assistant secretary of health, I look forward to working with you and coming to your office and discussing the particulars of the standards of care for transgender medicine."
Paul's questioning was not the first time that Levine has faced challenges because she is a transgender woman.
Levine rose to prominence in Pennsylvania last year when health officials around the country became more visible to the public in efforts to combat the coronavirus.
Attacks toward Levine on social media become vicious enough last summer that Pennsylvania Gov. Tom Wolf rebuked them in a statement.
"The COVID-19 pandemic has brought hate and transphobia into the spotlight through relentless comments and slurs directed at Secretary of Health Dr. Rachel Levine, who is a highly skilled, valued and capable member of my administration and Transgender," Wolf said. "Dr. Levine is a distinguished and accomplished public servant. She is committed to keeping Pennsylvanians safe and healthy, even those who direct hate-fueled attacks at her."
Levine responded to transphobic comments in July by vowing to remain focused on combatting the pandemic.
"I have no room in my heart for hatred, and frankly I do not have time for intolerance," Levine said a press conference in July. "My heart is full with a burning desire to help people, and my time is full with working toward protecting the public health of everyone in Pennsylvania. I will stay laser-focused on that goal.”
ABC News' Cheyenne Haslett contributed to this report.