Living in retirement successfully will depend upon making the right financial choices. Many people want to know if they should invest in a 401k plan or an IRA. The difference between the two is quite simple. A 401k plan is offered through your employer and an IRA is self-directed. Both plans have advantages because they are tax shelters. If you are working, and your employer offers a 401k plan, then you should take it. If you are not working or do not have a 401k, then you should begin your financial planning for retirement with an IRA. There are many different IRA plans; you should consult with your financial planner to determine which one is best for you.