New Delhi: Together with PayScale, Business Insider has released its second annual list of top 50 best employers in the United States. The companies were evaluated on both pay and happiness. For the second year, New Jersey biotechnology company Celgene Corporation topped the list as the Best Employer in America. In fact, many of the best companies are in the health-care industry.Companies were ranked according to scores calculated from the following factors: high job satisfaction, low job stress, high job meaning, high work-schedule flexibility, experienced median pay, and salary delta. Business Insider weighted pay twice in their calculations.Here is the top 20 among the list:20. Amgen CorporationHeadquarters: Thousand Oaks, CaliforniaMedian pay: $107,000 after five years.Employees report high rates of job meaning (82%) and work-schedule flexibility (77%). 19. BlackRock Inc. Headquarters: New YorkMedian pay: $115,000 after five years.This financial-services company has 10,500 employees. 18. Hershey Foods CorporationHeadquarters: Hershey, Penn.Median pay: $74,500 after five years.This food-processing company has over 12,000 employees. 17. Yahoo Inc.Headquarters: Sunnyvale, Calif.Median pay: $125,000 after five years.The company has over 11,000 employees, is based in Sunnyvale, Calif. Employees report high rates of work-schedule flexibility (90%) and job satisfaction (72%). 16. NetAppHeadquarters: Sunnyvale, Calif.Median pay: $118,000 after five years.This data-management company has over 12,000 employees. 15. Bristol-Myers Squibb CompanyHeadquarters: New YorkMedian pay: $106,000 after five years.This pharmaceutical company has 28,000 employees. Employees report high rates of work-schedule flexibility (84%) and job satisfaction (78%). 14. MasterCard WorldwideHeadquarters: Purchase, N.Y.Median pay: $109,000 after five years.Wal-Mart recently announced it was ditching Discover and choosing MasterCard Inc. to handle transactions for the merchants store-branded credit cards. 13. Qualcomm Inc.Headquarters: San DiegoMedian pay: $113,000 after five years.This semiconductors company has 26,500 employees. Employees report high rates of work-schedule flexibility (93%) and job satisfaction (80%). 12. Williams Companies Inc.Headquarters: Tulsa, OklaMedian pay: $79,400 after five years.This energy company has over 4,500 employees. 11. Marathon Petroleum Company LLCHeadquarters: Findlay, OhioMedian pay: $94,100 after five years.This oil and gas company has 26,000 employees. 10. Gilead Sciences Inc.Headquarters: Foster City, Calif.Median pay: $105,000 after five years.This biotechnology company has 5,000 employees. 9. PG&E CorporationHeadquarters: San FranciscoMedian pay: $108,000 after five years.This electricity and gas company has over 20,500 employees. 8. Google Inc.Headquarters: Mountain View, Calif.Median pay: $127,000 after five years.This Internet company has 48,000 employees. Employees report high rates of work-schedule flexibility (83%) and job satisfaction (81%). 7. Huntsman CorporationHeadquarters: Salt Lake CityMedian pay: $99,400 after five years.It is a chemicals company that has 12,000 employees. 6. PPL CorporationHeadquarters: Allentown, Penn.Median pay: $84,800 after five years.This energy company has 17,729 employees. 5. Anadarko Petroleum Corp.Headquarters: Woodlands, TexasMedian pay: $88,800 after five years.This oil and gas company has 5,200 employees. Employees report high rates of job satisfaction (83%) and work-schedule flexibility (82%). 4. Colgate-Palmolive CompanyHeadquarters: New YorkMedian pay: $101,000 after five years.This consumer-products company has 37,700 employees. 3. Celanese CorporationHeadquarters: Irving, TexasMedian pay: $103,000 after five years.This chemicals company has 7,400 employees. Employees report high rates of work-schedule flexibility (86%) and job satisfaction (74%). 2. Biogen IdecHeadquarters: Cambridge, Mass.Median pay: $96,100 after five years.This biotechnology company has 4,850 employees. It recently won FDA approval for its hemophilia B drug, marking a new frontier for the longtime leader in the development of drug treatments for multiple sclerosis. Employees report high rates of job meaning (87%) and work-schedule flexibility (87%). 1. Celgene CorporationHeadquarters: Summit, N.J.Median pay: $116,000 after five years.This biotechnology company has 4,700 employees. Employees report high rates of work-schedule flexibility (97%) and job meaning (93%).