Carnegie Mellon University

Health Insurance Basics

What is health insurance and why do I need it?

The cost of healthcare in the United States is high, so insurance helps protect you from serious health and financial risks.

Health insurance is a contract between you and an insurance company.  When you purchase and enroll in a plan, the company pays part of your medical costs when you get sick or hurt.  Many plans also cover basic preventive services. Learn more about why health insurance is important.

Premiums, Deductibles, Co-Pays, and Networks...

Health insurance terms can be confusing.  You can use the glossary to understand key terms. 

Why is my health insurance plan asking for my social security number?

Because everyone in the U.S. is required to have qualifying insurance, qualify for an exemption, or potentially pay a tax penalty, health plans are required to send the federal Internal Revenue Service (IRS) information about their members, including the member social security or other tax identification number.  Learn more about this requirement at

If you do not have a social security or other tax identification number, you can disregard the request. However, please note that health plans are required to request the information three times. If no response is received after the third request, the plan can provide the member’s date of birth.