A veto from Austria means the new status will not apply for land routes, due to concerns of an influx of refugees.
ADVERTISEMENTBulgaria and Romania joined Europe's Schengen area of free movement on Sunday, joining the rest of Europe travelling freely by air and sea without border checks.
The admission to the zone comes after a thirteen-year wait.
The membership is partial, however, as a veto by Austria means the new membership will not apply to land routes, which Vienna argued would lead to more asylum seekers travelling into Europe.
"This is a great success for both countries," President of the European Commission Ursula von der Leyen said.
"And a historic moment for the Schengen area — the largest area of free movement in the world. Together, we are building a stronger, more united Europe for all our citizens."
The Schengen zone will now comprise of 29 members – 25 of the 27 European Union member states as well as Switzerland, Norway, Iceland and Liechtenstein.
Romania's government said Schengen rules would apply to four seaports and 17 airports, including Bucharest's largest Otopeni airport.
Increased border police and immigration officers will be deployed to support passengers, and random checks will be carried out to detect people with false documents.
In January 2023 Croatia beat Romania and Bulgaria to become Schengen's 27th member, despite joining the EU later.
The Schengen Area was created in 1995 following the signing of the Schengen Agreement 10 years earlier between five member states of the European Economic Community: Germany, Belgium, France, Luxembourg and the Netherlands.
Several other agreements followed until the 2007 enlargement, integrating nine additional countries into the free movement area.