The Obama administration on Friday ended a 33-year ban on Medicare coverage for gender reassignment surgery — a major victory for transgender rights and a decision that is likely to put pressure on more insurers to provide coverage for such services.

The ruling by a Department of Health and Human Services board was in response to a lawsuit filed last year on behalf of Denee Mallon, 74, a transgender woman and army veteran from Albuquerque.

The blanket Medicare ban was put in place in 1981 when such surgeries were considered experimental. But now most medical groups, including the American Medical Association and the American Psychological Association, consider it a safe option for those suffering from gender dysphoria, a condition that is characterized by intense discomfort — or “incongruence,” according to the official definition — with one’s birth sex.

On Friday, the independent board, whose decisions are binding on HHS, said that medical studies published over the past three decades showed that the grounds for exclusion of coverage are “not reasonable” anymore and lifted the ban.

“This is long overdue,” said Judith Bradford, co-chair of the Fenway Institute, a Boston-based research center that focuses on LGBT health. “It brings government policy in line with the science around transpeople’s health-care needs.”

Although Medicare coverage is only for people 65 and older, and the transgender population makes up only about 0.3 percent of the U.S. adult population, private insurance plans often take their cues from Medicare on what should be considered a medically necessary covered treatment. As a result, the ruling is likely to open up more options for transgender individuals.

But in some ways, the ruling was more important from a symbolic standpoint than a practical one. Medical professionals say very few people opt for surgical interventions. And the cost to insurers that offer coverage — which can be anywhere from $10,000 to $50,000 per surgery — is often negligible in relation to their entire patient pools, according to several studies.

Administration officials originally sought to overturn the ban in 2013, but the attempt prompted a backlash among social conservatives and religious groups who oppose taxpayer funding for such procedures.

Leanna Baumer, a senior legislative assistant with the Family Research Council, said that the ruling “ignores the complexity of issues” surrounding gender identity issues.

“Real compassion for those struggling with a gender identity disorder is to offer mental health treatments that help men and women become comfortable with their actual biological sex — not to advocate for costly and controversial surgeries subsidized by taxpayers,” she said.

Frank Schubert, national political director for the National Organization for Marriage, said he also objects to the decision for moral reasons and that it does not encourage children “to respect who they are, how they were born.”

One of the attorneys who worked on the case — which was filed by the American Civil Liberties Union, Gay & Lesbian Advocates & Defenders and the National Center for Lesbian Rights — said that decades of bias and prejudices have resulted in a crisis in health care for some transgender people.

“For someone who cannot get treatment, the impact can be devastating,” Jennifer Levi said. They can be depressed, have serious problems with self-esteem, and have difficulty working and forming social relationships, she added.

For many, transitioning to another gender is a lengthy and deeply private process that can take years. It often involves psychotherapy and hormone treatments while living as a member of his or her preferred gender. Some may decide for more radical changes through surgery — which can include vocal-cord modifications, breast implants and mastectomies, and modifications of sexual organs. Mallon, who was born a man, was seeking to have genital reconstruction.

Patients covered under Medicare will not be guaranteed coverage for surgeries under Friday’s decision; they will have to justify their need just as they have to for any other medical treatments. The ruling does not apply to Medicaid, the health program administered by states for low-income individuals and families.

The federal decision comes at a time of radical change in attitudes in transgender care across the country.

California, Colorado, Connecticut, Oregon and Vermont have affirmed the idea that transition care for transgender individuals should be considered an essential part of medical coverage. In February, D.C. Mayor Vincent C. Gray (D) said the city would recognize gender dysphoria as a medical condition — effectively forcing insurers to cover gender-reassignment surgery.

Private companies are also adapting their coverage. According to the Human Rights Campaign, a gay and transgender advocacy group, no Fortune 500 companies offered transgender benefits in 2002. By 2012, 19 percent did. And in 2014, the number increased to 28 percent.

Jamison Green, president of the World Professional Association for Transgender Health, a nonprofit educational group that works with doctors, said that while Friday’s ruling was a step in the right direction in ending discrimination in insurance coverage, there is still more work to be done.

He explained, for example, that some transgender men have had trouble getting coverage for mammograms or hysterectomies when they developed fibroids or even cancer. Green said that in some cases, the issues can be resolved by having the person change his or her official gender on paper with an insurer. But he said for some, such a requirement could be psychologically damaging, especially if the person is already struggling with sexual identity.

“The net effect is highly prejudicial,” Green said. “It is about people using the opportunity to punish transgender individuals for being different. These are the things we need to resolve.”

In a statement Friday, Mallon said that the “decision means so much to me and to many other transgender people.”

“I am relieved to know that my doctor and I can now address my medical needs,” she said, “just as other patients and doctors do.”