When a spouse passes, a lack of knowledge about the finances can cause increased emotional and financial stress at the most inopportune time, according to The New York Times in "Death Is Inevitable. Financial Turmoil Afterward Isn't."
This is a mostly avoidable problem.
In most cases, the non-involved spouse just needs to be informed beforehand about how the family finances are arranged and managed. The spouse needs to be aware of insurance and retirement plans. They also needs to know where to find the documentation for those plans.
Estate planning is particularly important, since it provides an opportunity for both spouses to discuss their finances with an attorney and to make arrangements for what should happen if the spouse who typically manages everything passes away. This also allows the other spouse a chance to reflect on whether he or she even wants to (or feels capable of) handling everything.
The surviving spouse may sometimes be more comfortable having someone else in charge of the finances through a trust or other legal entity.
An estate planning attorney can guide you through the process of creating an estate plan that best fits your unique circumstances.
Reference: New York Times (Jan. 13, 2017) "Death Is Inevitable. Financial Turmoil Afterward Isn't."