An insurance plan that is sold on the Federally Facilitated Marketplace (Healthcare.gov) is considered a “marketplace” plan. The Federal Marketplace is also often referred to as “the exchange” and therefore plans offered via the exchange are commonly referred to as “on-exchange” plans. Tax subsidies from the government can be offered for these plans, if the applicant meets the governments criteria for subsidies. Health insurance plans can still be sold “off the exchange” by individual carriers or brokers, but applicants would not be able to receive tax subsidies.
Apart from the tax subsidies and the application process on healthcare.gov, there is nothing fundamentally different about “on-exchange” plans, as all health insurance plans must meet the requirements of the Affordable Care Act.