Pro rata vs per stirpes comes down to one question: if a beneficiary dies before you do, should their share go to the other beneficiaries or down to that person’s children? Pro rata (also called per capita) splits your estate equally among the beneficiaries who are still alive, so a deceased beneficiary’s share gets absorbed by the survivors. Per stirpes keeps that share with the deceased beneficiary’s family line, passing it down to their descendants. The two methods produce identical results when everyone named is alive, and very different results when someone isn’t.
What Each Term Actually Means
Per capita is Latin for “by the head.” An estate divided per capita gives each named beneficiary the same share. Three children named in a will each take one-third. The method counts individuals, not family lines, so a grandchild with four siblings gets the same share as a grandchild who is an only child.
Pro rata technically means “in proportion,” which allows unequal splits if the document assigns different percentages. In practice, estate planners use pro rata and per capita almost interchangeably when no special weighting is specified, because dividing equally among a group is the same as dividing proportionally when every proportion is equal. Some attorneys write “share and share alike” to signal the same thing. Unless your document assigns specific percentages, pro rata means equal shares.
Per stirpes is Latin for “by the roots” or “by the branch.” Instead of counting heads, it divides the estate into branches at the first generation of beneficiaries. Each branch gets an equal share. If the person at the top of a branch has already died, that branch’s share flows down to their descendants. A parent with three children creates three branches, each entitled to one-third, regardless of how many people sit inside any given branch.
The Scenario Where They Diverge
Everything turns on one situation: a named beneficiary dies before the person whose estate is being distributed. Picture a $900,000 estate left equally to three children, and one of those children dies first, leaving behind two children of their own.
Under pro rata, the deceased child’s share disappears from their family line. The two surviving children split the entire $900,000, taking $450,000 each. The two grandchildren receive nothing from this distribution. They are effectively disinherited by the method itself, not by any deliberate choice.
Under per stirpes, the estate still splits into three $300,000 branches. The two surviving children each take their $300,000. The deceased child’s $300,000 flows down to that child’s two kids, who split it equally at $150,000 each. The grandchildren receive what their parent would have received.
This is the reason most estate attorneys default to per stirpes for families with children and grandchildren. It prevents the accidental disinheritance of an entire branch because one person died in the wrong order.
A Third Option: Per Capita at Each Generation
Per stirpes has a quirk that bothers some people. Suppose your three children are Alice, Bob, and Carol. Bob has two children and Carol has one. Both Bob and Carol die before you. Under per stirpes, Alice takes her $300,000. Bob’s $300,000 branch is split between his two kids at $150,000 each. Carol’s $300,000 goes entirely to her one child. The grandchildren end up with wildly different amounts purely because of how many siblings each has.
Per capita at each generation fixes this. Alice still takes her one-third. But instead of running Bob’s and Carol’s shares down their separate branches, the method pools the $600,000 the deceased children would have received and divides it equally among all grandchildren at the next generation. Bob’s two kids and Carol’s one kid each receive $200,000.
The Uniform Probate Code uses per capita at each generation as its default for intestacy, and a growing number of states have adopted it. Even if your own documents say something different, this is the rule that may apply if you die without a will.
Strict Per Stirpes vs. Modified Per Stirpes
“Per stirpes” by itself is ambiguous, and the ambiguity matters when an entire generation is already gone.
Strict (or traditional) per stirpes always divides the estate at the children’s generation, even if every child has already died. If all three of your children predeceased you, strict per stirpes still creates three branches at the children’s level and sends each one down to that child’s descendants. A grandchild whose parent was an only child in the branch takes the full one-third; a grandchild who shares a branch with a sibling takes one-sixth.
Modified per stirpes (sometimes called per stirpes by representation) starts the division at the first generation that actually has a living member. If all your children are dead but grandchildren are alive, the estate is divided equally among those grandchildren directly, rather than being filtered through their deceased parents’ branches first. In the three-grandchildren example above, modified per stirpes gives each grandchild an equal one-third; strict per stirpes gives two of them one-sixth and the third a full one-third.
Many people who write “per stirpes” in their documents don’t know which version their state applies. If you have a preference, spell it out in plain language instead of relying on the Latin phrase alone.
Who Counts as a Descendant
Per stirpes sends shares to a deceased beneficiary’s “descendants,” which raises a question people often get wrong. In virtually every state, legally adopted children are treated identically to biological children for inheritance. An adopted grandchild inherits under per stirpes the same way a biological grandchild would.
Stepchildren and step-grandchildren do not. Unless they have been formally adopted, they have no inheritance rights under a per stirpes designation, no matter how closely they were tied to the family. If you want to include them, name them individually in your estate documents. The Latin phrase follows legal parentage, not emotional bonds.
Why Your Beneficiary Forms Matter More Than Your Will
Retirement accounts, life insurance policies, and payable-on-death bank accounts pass directly to named beneficiaries outside of probate. The beneficiary form controls, not the will. The default on most of these forms works like pro rata: if a named beneficiary dies first, the surviving named beneficiaries split the proceeds, and the deceased beneficiary’s children get nothing.
Some custodians now offer a per stirpes checkbox. Fidelity’s IRA beneficiary form, for example, lets you check a per stirpes box so a deceased beneficiary’s share passes to that person’s descendants. Not every institution offers this. Federal Employees Group Life Insurance (FEGLI) rejects per stirpes designations on its forms and advises naming your estate as the beneficiary so the proceeds pass through your will, where per stirpes language can take effect.1U.S. Office of Personnel Management. What Is a Per Stirpes Designation?
Review every beneficiary form you’ve signed. If you want per stirpes treatment on a retirement account or insurance policy, confirm the form actually supports it. If it doesn’t, either name contingent beneficiaries explicitly or route the proceeds through your estate and handle the distribution in your will or trust.
How to Choose
Pro rata keeps things simple and equal among the survivors, but it can cut out grandchildren entirely if one of your children dies first. Per stirpes protects family branches and is the better fit for most people who want their wealth to flow down the family tree the way they’d expect. Per capita at each generation sits between the two, treating same-generation descendants equally regardless of which branch they came from.
Whichever method you choose, state your intent clearly in both your will or trust and on every beneficiary form you’ve signed. Inconsistencies between these documents are what lead to probate disputes. If your will says per stirpes but your IRA beneficiary form defaults to pro rata, the IRA follows the form. The result can be the opposite of what you intended.