State laws are similar, but differences can turn out to be important.
If you relocate to another state, it is important to revisit your estate plan because there are a number of variables that have an impact on the plan, according to The Times Herald in "Moving can affect your financial planning."
Generally speaking, if a will you had drafted was valid in the state in which it was drafted at the time it was drafted, the other states will consider it to be valid.
Trusts are valid in every state, since the state in which they were created always governs over the trust.
Most of the time your estate plan will be valid in your new state. However, there can be some issues, especially if you purchase real estate in your new home state. Some states have particular rules about how real estate has to be handled.
You should also be aware that your new state could have tax laws that are different than your old state. Something you have done in your estate plan might still be legal and valid, but it might not be tax-wise.
It would be prudent to obtain the advice of an estate planning attorney in your new state of residence, in case your plan needs updating.
Reference: The Times Herald (Dec. 1, 2017) "Moving can affect your financial planning."