Client sometimes ask how often they should review their estate plan. I tell clients that checking up on your legal affairs is something they should do. It's not a vaccination - you don't create an estate plan and then forget about it. There are some important reasons for this. First of all, an estate plan is exactly that - a "plan." Therefore, if circumstances change, you may need to change or alter your plan depending on those circumstances. So I tell clients they should revisit their estate plan if there is a major life change - a birth of a child, a divorce, a new marriage, a beneficiary who might be facing some challenges like bankruptcy, divorce, litigation, etc. There are times when you have to revisit the plan and make changes accordingly. I liken it to going to the doctor - people don't just go to the doctor one time and then never again. Ideally you should be going to your doctor regularly in case there are any changes that require a new approach, new medication, new diet, etc.
Also, laws changes as the years go on. Therefore, you want to make sure your legal documents are current and reflect the current laws. That doesn't mean you need to make a change every time there is a minor change in the law. In many cases, minor changes in the law won't really affect your overall plan. However, just like there are changes in medicine that may affect what a doctor recommends that you do, your lawyer might recommend changes or updates to keep up with current law changes that affect your plan.
Finally, if your documents are too old, some places may be reticent to honor your documents when the time comes. As a practical matter, your will and/or your living trust probably won't be too affected by that. It is common for people to use old wills or old living trusts. However, if you present a durable power of attorney or health care documents that are 10 years or older, some places might say, "Do you have anything newer than this?" Although your documents may be perfectly legal, some institutions may be reluctant to honor them if they are too "old." What is too old? Some places don't like document older than 5 years old. Some other places worry about documents that are more than 10 years old. I usually recommend clients update their health care documents and the power of attorney document every 10 years at least. That way, they always have current documents and are less likely to run into such resistance. The reason some places are concerned about older documents is because they worry that someone is trying to trick them. They worry about fraud. If a document is more than 10 years old, they worry there might be a newer document and someone is trying to use an older document instead. If the documents presented are fairly recent, the facility is generally more confident the document is legitimate and indeed what the client wants.
The general rule of thumb I give clients is to revisit their estate planning documents every 7 years. That's because 5 years is probably too soon and 10 years might be too long. Plus, people tend to remember the "lucky" number 7. Of course, they should also review their documents if there is a major life change as indicated above.