People who do not fit the biological definitions of male or female in Germany can now be legally identified as a third option on official records from January 1.
The new category, "divers," which roughly translates to "other" or "miscellaneous," is included on driving licenses, birth certificates and other official documents.
Until now, the only option for those who do not identify themselves as male or female was to leave the gender entry blank.
The law applies to those with a medical certificate
The ruling will apply to those born as intersex and parents will need a doctor's certificate to mark their child under the new category.
Adults registered as male or female will also need a medical certificate to change their gender marker.
The update to the constitution was approved in parliament in December 2018 after a German court ruled that there must be a third gender option.
The case that set the change in motion was opened by a German citizen identified only as Vanja.
Born in 1989, Vanja's initial attempts to change her gender from female to intersex/diverse were rejected.
Backed by gender advocacy group Third Option, Vanja sued the German government.
After a legal battle that lasted four years, a top court in Germany in November 2017 ordered the government to pass a law to bring in the third category.
The move made the country the first in the European Union to allow parents to designate their intersex children as third gender.
Campaigners say the change 'excludes' many people
While activists described it as a "small revolution," some LGBT+ campaigners said the new measures did not go far enough.
"If people feel seriously and sustainably not male or female, the law must allow them to legally register their status as they define it,” Germany’s Association of Lesbians and Gays said.
It said lawmakers should “make the category ‘divers’ open to all individuals who need it and want it,” without requiring official medical statements.
Third Option said in a statement that the law "excludes many people who have been waiting for this law."
And a spokesperson from the organisation told Euronews the change does not apply to transgender individuals.
It said those excluded include "inter people who cannot or do not want to present a certificate, as well as non-binary people, people who are not intersex and neither "woman" nor "man"."
When the issue was first raised in parliament, legislators from the party Alternative for Germany (AfD), opposed the bill.
“Gender designation has been an objective fact since the beginning of humanity, just like age and body shape,” said Beatrix von Storch, am AfD lawmaker.
The United Nations said between 0.05% and 1.7% are born with intersex traits in the world.
"Intersex is an umbrella term used to describe a wide range of natural bodily variations," the UN said. "In some cases, intersex traits are visible at birth while in others, they are not apparent until puberty. Some chromosomal intersex variations may not be physically apparent at all."