Apple Maps does not show a border between Crimea and Russia to the east.
Apple says it is "looking deeper" at how it deals with disputed borders.
Ukraine has criticized the technology giant for showing Crimea as part of Russia's territory in its Maps and Weather apps.
An Apple spokeswoman said the company follows international and domestic laws and that the change, which is only for users in Russia, was made because of new legislation in the country.
The Russian annexation of Ukraine's Crimea in 2014 was condemned by much of the international community.
In a statement, Apple emphasized, "We have not made any changes to Apple Maps regarding Crimea outside Russia.
"We review international law, as well as relevant US and other national laws, before determining labeling on our Maps and making changes if required by law."
Apple added that as a result of its analysis of how disputed borders are handled, it may make more changes in the future.
"Our intention is to ensure that our customers can use Maps and other Apple services anywhere in the world."
The changes to Apple's Crimean map for users in Russia were announced earlier this week by the State Duma, the lower house of the Russian parliament, in a statement that described the former borders as an "inaccuracy".
"Crimea and Sevastopol now appear on Apple devices as Russian territory," the statement said.
Russia treats the naval port city of Sevastopol as a separate region.
Apple has been in talks with Russia for several months and hoped to keep Crimea as an undefined territory, part of Russia and Ukraine.
Google, which produces its own popular map application, also shows Crimea as belonging to Russia when viewed from the country. This change happened in March.
Apple's action brought strong condemnation from Ukraine.
Ukrainian Foreign Minister Vadym Prystaiko tweeted: "Apple, please stick to high tech and entertainment. Global politics is not your strong side."
"We think the Ukrainians don't thank @Apple on this Thanksgiving. So let's all remind Apple that #CrimeaIsUkraine is under Russian occupation – it's not their sovereignty," he tweeted.
Former Russian chess champion Garry Kasparov added his voice, calling the decision "unacceptable appeasement".
He added, "Software is soft power. American technology companies must uphold the values of innovation that made their success possible, and not bow to dictators for a little extra money they don't even need."