The simple answer is "yes".
Starting January 1, 2014, there is an individual requirement to have qualified health insurance or pay a penalty, unless you qualify for an exception. Qualified health insurance can include Medicaid, Medicare, CHIP, Tri-Care, or health policies issued through an employer or to you personally. This is sometimes referred to as the "Individual Mandate".
Exchanges have been created to offer low-cost solutions to the health insurance requirement to make sure that everyone has access to affordable coverage options.
Just like most every rule, there are exceptions. Some people will not have to pay a penalty for not having insurance based on exceptions such as income level or religious objection. Learn more about the requirement and exceptions here.
If you do not have health insurance and do not qualify for an exception, you will be subject to a penalty starting in 2014. You can learn more about the penalties here.