March 20 (Reuters) - Disruptions from the Feb. 21 hack
at UnitedHealth Group's tech unit created a cash crunch
for small healthcare providers and led to a U.S. health
department probe into whether there was a breach of protected
health data.
    The exact impact of the hack on patient data is not yet
clear, but it adds to the growing list of increasingly
disruptive cyberattacks on U.S. healthcare companies.
    The following is a list of the biggest IT hacks in the
sector where patient data were breached: 
    
                                                    Type of
 Name of          Year   Individuals    company 
 company                 affected       
                                        
 Anthem Inc    2015      78,800,000     Health insurer
 American      2019      26,059,725     Medical debt
 Medical                                collector  
 Collection                             
 Agency                                 
 HCA           2023      11,270,000     Hospital operator 
 Healthcare                             
 Premera Blue  2015      11,000,000     Health insurer
 Cross                                  
 Excellus      2015      9,358,891      Health insurer
 Health Plan,                           
 Inc                                    
 Perry         2023      8,952,212      Medical transcription
 Johnson &                              service provider 
 Associates                             
 (PJ&A)                                 
 Managed Care  2023      8,861,076      Dental insurer
 of North                               
 America                                
 (MCNA                                  
 Dental)                                
 Welltok Inc   2023      8,493,379      Healthcare technology
                                        provider
 23andMe       2023      6,900,000*     Genetic testing
                                        company  
 PharMerica    2023      5,815,591      Healthcare Provider
 Corp                                   
 Source: Government data, company reports
    Note: Hackers gained access to 14,000 customer accounts on
the 23andMe website. From those 14,000 accounts, hackers
accessed non-health information, such as names of about 5.5
million customers' relatives and 1.4 million customers' extended
family members.

 (Reporting by Sneha S K and Mariam Sunny in Bengaluru)