Glossary term
Life Expectancy Factor
A life expectancy factor is the IRS table number used to calculate required minimum distributions from certain retirement accounts.
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What Is a Life Expectancy Factor?
A life expectancy factor is the table number used to calculate required minimum distributions from certain retirement accounts. For many IRA owners, the factor is the applicable denominator from IRS life expectancy tables in Publication 590-B.
The factor converts an account balance into a required distribution amount. A larger factor generally produces a smaller required withdrawal; a smaller factor generally produces a larger required withdrawal.
Key Takeaways
- Life expectancy factors are used in required minimum distribution calculations.
- The applicable table depends on the account owner, beneficiary, and spouse-beneficiary situation.
- The factor is applied to the prior year-end account balance.
- Inherited accounts can use different rules from an owner’s own retirement account.
How the RMD Calculation Works
The basic RMD framework divides the prior December 31 account balance by the applicable life expectancy factor or denominator. The table used depends on the facts. IRA owners often use the Uniform Lifetime Table, while certain spouses and beneficiaries may use other tables.
The prior year-end account balance is the account value used for the calculation. The life expectancy factor is the IRS table denominator for the person and situation. The result is the minimum amount that must be distributed for that year, though the account owner may withdraw more.
Table | Common use |
|---|---|
Uniform Lifetime Table | Many account owners calculating lifetime RMDs. |
Joint and Last Survivor Table | Account owner whose sole beneficiary spouse is more than 10 years younger. |
Single Life Expectancy Table | Some inherited IRA and beneficiary calculations. |
Why the Factor Changes
Life expectancy factors generally decline as the account owner ages. That means the required distribution percentage usually rises over time. For inherited accounts, the rules can be more complex because the factor may be reduced year by year, reset under newer tables, or replaced by a 10-year rule depending on the beneficiary and timing.
What to Watch
Using the wrong factor can cause an RMD shortfall. That can create tax penalties, correction work, and confusion across multiple accounts. People with inherited accounts, much younger spouse beneficiaries, multiple IRAs, or employer plans should be especially careful about which table applies.
Example
If an IRA owner has a prior year-end balance of $100,000 and the applicable factor is 25, the RMD is $4,000. If the factor is 20, the RMD is $5,000. The lower factor produces a larger required withdrawal because the table assumes the balance is being distributed over a shorter remaining period.
The example is simplified. Actual RMD calculations can change when there are multiple accounts, inherited accounts, spouse beneficiaries more than 10 years younger, year-of-death rules, or plan-specific restrictions.
The Bottom Line
A life expectancy factor is the IRS denominator used in many RMD calculations. It is a small number on a table, but it controls how much must come out of certain retirement accounts each year.