Over a six-month period, the US government issued Apple with 1,015 law-enforcement requests for data on 5,192 accounts.
Apple discloses the figures in its latest report outlining the total number of information requests from governments. The report covers requests by governments around the world between July 1 and December 31, 2015.
The number of accounts affected is nearly double the figure for the first half of 2015, when Apple received 971 requests for 2,727 accounts.
Apple reports the number of requests it receives for accounts and devices, as well as the number of national-security letters, emergency requests, and account-deletion requests.
Most requests Apple receives are for devices. However, the more sensitive requests are for access to account details about specific Apple IDs, email addresses, telephone numbers, credit-card numbers, and other personal identifiers.
The FBI could create "ghost" iPhone updates that imitate legitimate Apple software.
The number of account requests, which can arrive as warrants, subpoenas or court orders, are also significant, given Apple's recent court battle with the Justice Department over access to encrypted iPhones.
Apple disclosed some data for 82 percent of the requests it received, totalling 4,411 accounts. This figure includes instances where Apple may have provided email addresses, telephone numbers, credit-card numbers, or personal identifiers used for accessing iCloud, iTunes, or Game Center.
The company turned over content for 322 accounts and non-content data for 509 accounts. Non-content data covers subscriber information or for example, purchasing history, whereas content data can include anything backed up to iCloud, such as email, contacts, calendar, and photos.
Apple also objected to 116 requests and didn't turn over any data for 184 accounts.
During the period, Apple also received between 1,250 and 1,499 national security-related gag orders, affecting between 1,000 and 1,249 accounts.
Tech companies are forbidden from reporting the precise number of national-security orders they receive in a period. Microsoft recently reported receiving fewer than 500 national-security orders for between 15,500 and 15,999 accounts during the first half of 2015.
The number of US Apple accounts affected by government requests exceeded those of every other nation except China, where Apple received 32 requests for 6,724 accounts.
However, Apple said China's requests were predominantly related to phishing investigations. Apple turned over data on 5,082 accounts in China.
The UK government filed 208 requests for account data, affecting 248 accounts. This figure made up more than a third of the total number of account requests Apple received across Europe, the Middle East, India and Africa.
In the UK, Apple disclosed content data for 121 accounts and non-content data for 87 accounts. It also objected to 45 requests.
The German government filed 130 requests for 150 accounts, while France filed 60 requests for 65 accounts. Apple disclosed some data for 18 accounts in France and 72 accounts in Germany.