The Affordable Care Act (ACA), also known as ObamaCare, made significant changes to the way that health insurance is purchased. One of the most important shifts is that most coverage types can only be purchased during certain open enrollment periods, except in special circumstances such as having given birth or gotten married.\nThere are a variety of coverage types, and many have their own specific enrollment periods. Following are the types of insurance available and the timeframes in which you can purchase them.\nACA Marketplace Health Insurance\nFor Americans who don\u2019t have health insurance available through an employer, the ACA Marketplace is a one-stop shop to compare and purchase health insurance. The Marketplace has a specific open enrollment period, which may be modified each year by the President\u2019s Administration. This year\u2019s open enrollment period began November 15, 2014, and will end February 15, 2015. To obtain insurance outside this timeframe, you must qualify for a special enrollment period.\nEmployer-Based Health Insurance\nIf you obtain your insurance through an employer, you will also have a specific enrollment timeframe to choose coverage and make any needed changes. Again, you will need to qualify for a special enrollment period to make changes outside of these dates. The dates for employer-based open enrollment vary depending on the company, so be sure to check with your human resources department for details.\nMedicare Enrollment\nSeniors can make decisions about their Medicare Part D prescription plans and their Medicare Advantage plans during the Medicare open enrollment period. This period is the same every year, running from October 15 through December 7. During this time, Medicare beneficiaries can switch from Original Medicare to Medicare Advantage, change Medicare Advantage plans, join a Medicare Prescription Drug Plan, and more.\nThose who have Medicare Part A and want to sign up for Medicare Part B can do so during the Part B General Enrollment Period, which is April 1 \u2013 June 30 each year.\nFor seniors who are newly eligible for Medicare, there is a special enrollment period that starts three months before the month of your 65th birthday and ends three months after that month. You can choose plans that will begin the first of the month after you select your options.\nMedicaid and Children\u2019s Health Insurance Program (CHIP)\nMedicaid and CHIP are not subject to specific enrollment periods. For those who qualify, plan selections can be made anytime and coverage usually begins immediately. For more information, contact the Medicaid office in your state.\nSmall Business Health Program (SHOP)\nSmall businesses can select insurance plans either through the SHOP Marketplace or outside the Marketplace throughout the year. Through most of the year, insurers can impose a minimum participation requirement on businesses and decline to issue the policy if that participation isn\u2019t met. From November 15 \u2013 December 15 each year, employers can purchase plans without meeting this requirement.\nThe SHOP Marketplace is only available to employers with 50 or fewer full-time equivalent (FTE) employees. Starting in 2016, SHOP will be available to businesses with up to 100 FTEs.\nAmericans can purchase health insurance in a variety of ways depending on their age and life situation. While there are several different open enrollment periods throughout the year, make sure to find the type of coverage that best fits your current situation. By learning about the different timeframes and plans, you\u2019ll be ready when the time comes to make your personal health insurance decision.