社会保险(social insurance)
针对各种经济风险（如因疾病、年老以及失业导致丧失收入）提供保障的强制性的公共保险计画。社会保险被认为是社会保障的一种类型，虽然有时候这两个词语也可以相互替换使用。第一批强制性的国家社会保险规画是由德国在俾斯麦执政时期建立的：包括1883年的健康保险，1884年的工人抚恤金，以及1889年的老年与伤残退休金。很快的，奥地利和匈牙利也起而效仿。1920年後，社会保险在欧洲以及西半球迅速推广。美国起步稍迟，1935年才通过「社会安全法案」。现在美国的社会保障提供退休金、六十五岁以上老人的医疗保健以及伤残保险。社会保险的保险费用缴纳通常是强制性的，可能由被保险人的雇主缴纳，也可能由政府以及被保险人个人缴纳。社会保险资金通常自我融资，将各方缴纳的款项投放於特定的基金来增值。亦请参阅unemployment insurance、welfare。
English version：
social insurance
Compulsory public-insurance program that protects against various economic risks (e.g., loss of income due to sickness, old age, or unemployment). Social insurance is considered one type of social security, though the two terms are sometimes used interchangeably. The first compulsory national social-insurance programs were established in Germany under Otto von Bismarck: health insurance in 1883, workers' compensation in 1884, and old-age and disability pensions in 1889. Austria and Hungary soon followed Germany's example. After 1920, social insurance was rapidly adopted throughout Europe and the Western Hemisphere. The U.S. lagged behind until the passage of the Social Security Act in 1935. Social Security in the U.S. now provides retirement benefits, health care for persons over 65, and disability insurance. Social-insurance contributions are normally compulsory and may be made by the insured person's employer and the state as well as by the individual. Social insurance is usually self-financing, contributions being placed in specific funds for that purpose. See also unemployment insurance, welfare.