Amazon.com Inc said on Tuesday it launched a pilot healthcare program for its employees and their families to provide primary services such as vaccination and physical therapy.

The move comes at a time when the world's largest online retailer has been facing intense scrutiny from U.S. lawmakers and unions over its limited measures to protect staff from the COVID-19 pandemic.

Under the program, a partnership with national medical group Crossover Health, 20 health centers would be built over the next few months across five cities near the e-commerce giant's fulfillment centers.

The first center will be located in Las Colinas, Texas.

(Reporting by Neha Malara; Editing by Shinjini Ganguli) ((neha.malara@thomsonreuters.com; 646 223 8780 - 3401;))