(CNN) The Trump administration is considering a new proposal to narrowly define "sex," a shift that could upend the rules and programs for transgender people in America.

The proposal, first reported by The New York Times, is just one of many ways that the administration has sought to roll back Obama-era protections for transgender people, including in schools, at work and in the military.

Here's a look at some of the main policy proposals the administration has taken toward transgender people and how they differ from the Obama administration.

Proposal to narrowly define sex

The Department of Health & Human Services is considering defining "sex" under Title IX as solely male or female as a biologicaland unchangeable condition determined by genitalia at birth, according to The New York Times

"Sex means a person's status as male or female based on immutable biological traits identifiable by or before birth," the department proposed in the memo, which has been drafted and circulating since last spring, according to The Times. "The sex listed on a person's birth certificate, as originally issued, shall constitute definitive proof of a person's sex unless rebutted by reliable genetic evidence."

The proposed definition, if adopted, would erase federal recognition for Americans who identify as a gender different than the one they were born with, the newspaper reports. The change would also mark a shift from the Obama administration, which expanded the legal definition of gender in several instances.

The issue is particularly relevant to rules at the Department of Education on sex discrimination in schools and colleges, as well as at Health & Human Services for health programs receiving federal funding. Title IX prohibits sex-based discrimination in education programs or activities receiving federal funds.

HHS spokesperson Caitlin Oakley said that the department is following a court order blocking the Obama-era a rule on gender identity.

"The court order remains in full force and effect today and HHS is bound by it as we continue to review the issue," Oakley said. "Everyone deserves to be treated with respect and HHS's Office for Civil Rights will continue to vigorously enforce all laws as written and passed by Congress, prohibiting discrimination in healthcare on the basis of race, color, religion, national origin, sex, age, and disability."

The Human Rights Campaign, a prominent LGBTQ rights group, said the proposal was part of a "consistent, multi-pronged campaign by the Trump-Pence White House over the past two years to undermine the rights and welfare of LGBTQ people."

"Defining 'sex' in this narrow language tailored to the talking points of anti-equality extremists is part of a deliberate strategy to eliminate federal protections for LGBTQ people," HRC President Chad Griffin said in a statement Sunday.

Tami Fitzgerald, executive director of the conservative NC Values Coalition, told The Times that the Trump administration's position was "critical in this confused world to define these terms as Congress intended them when federal programs such as Title IX were passed."

Trump signs directive banning transgender military recruits

A protester displays a placard during a demonstration in New York, on July 26, 2017.

Transgender people had been banned from serving openly in the military, until a directive in 2016 under Obama's defense secretary, Ash Carter. Carter allowed for a yearlong training and implementation process to give the Pentagon time to determine how it would accept new transgender recruits into the military.

But in a series of tweets last July, President Donald Trump announced that "After consultation with my Generals and military experts," the US "will not accept or allow transgender individuals to serve in any capacity in the U.S. Military," citing the "tremendous medical costs and disruption" they would entail.

The policy, announced on the President's personal Twitter, came as a surprise to military officials . An earlier analysis from the Rand Corporation, commissioned by the Obama Defense Department, concluded that allowing transgender people to serve in military would have a "minimal impact" on readiness and health care costs, largely because there are so few.

Despite Trump's announcement, a federal judge ruled that the military had to accept transgender people. One transgender person joined , the Pentagon said in February.

The White House announced another policy in March that would ban most transgender people from serving in the military, except under certain limited circumstances. The ban has since been blocked by a federal court.

LGBT advocacy groups have said the policy is a discriminatory attack on those who have volunteered for their country.

"The Trump-Pence administration's continued insistence on targeting our military families for discrimination is appalling, reckless, and unpatriotic," said Ashley Broadway-Mack, president of the American Military Partner Association and spouse of an active duty Army officer.

Sessions says civil rights law doesn't protect transgender workers

Attorney General Jeff Sessions reversed an Obama administration guidance and determined that the 1964 federal civil rights law does not protect transgender workers from employment discrimination.

Sessions announced the change in a memo to federal prosecutors in October 2017.

"Title VII's prohibition on sex discrimination encompasses discrimination between men and women but does not encompass discrimination based on gender identity per se, including transgender status," he wrote.

Title VII prohibits employment discrimination based on race, color, religion, sex and national origin. Department of Justice spokesperson Devin O'Malley said that the Obama administration had expanded beyond what the law provided.

LGBT rights advocates criticized Sessions' decision.

"According to Sessions, an employer is free to hang a 'Transgender Need Not Apply' sign in their window. Fortunately, he is dead wrong on the law," said Mara Keisling, executive director of the National Center for Transgender Equality, in a statement last year.

Public schools no longer obligated to allow transgender students in bathroom

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Just a month into his presidency, the Trump administration withdrew Obama-era protections of transgender students in public schools that let people use the bathrooms and facilities that correspond with their gender identity.

The decision was a reversal from Obama's departments of Education and Justice, which issued the original guidance in May 2016 in a " Dear Colleague " letter to school districts and colleges that receive federal funds. The Obama era guidance was based on the administration's interpretation of Title IX, which bans discrimination based on sex.

Opponents of Obama's move had challenged it in federal court and won a national injunction preventing that guidance. In February 2017, the Trump administration's Justice Department withdrew from a court hearing that argued against the injunction.

The Trump administration letter to schools reasoned that the Obama-era guidance did not provide "extensive legal analysis" to support its position.

"As President Trump has clearly stated, he believes policy regarding transgender bathrooms should be decided at the state level," the White House said in a statement.