The "1+ Spasm" Rule Explained
1+ Spasm is shorthand Social Security uses for a specific rule about work credits: you earn one work credit for each quarter of the year in which you earn at least a certain amount of money, no matter how much you earn above that threshold. The word "spasm" does not refer to a medical condition — it is an acronym meaning "substantial gainful activity per quarter month" (though the exact origin varies in different Social Security offices). What matters is that you cannot earn two credits in a single quarter, even if you earn a very high income that quarter.
This rule affects how quickly you build the work credits you need for SSDI. If you work steadily throughout the year, you will earn four credits per year — one per quarter. If you work only sporadically or earn all your income in one or two months, you may earn fewer credits that year, which means it takes longer to reach the 40 credits (or 20 credits if you are under 31) that SSDI requires.
Key Takeaways
- You earn one work credit per quarter only if you earn at least a set dollar amount that quarter; earning more in that quarter does not give you extra credits.
- The dollar amount required per quarter changes each year and is set by Social Security based on national wage trends.
- Spreading your work income across all four quarters of the year is the fastest way to build work credits, because you can earn a maximum of four credits per year.
- If you earn all your income in one or two months, you will earn only one or two credits that year, even if your total income is very high.
- Work credits earned in past years stay on your record and count toward your SSDI requirement, even if you stop working later.
How the Dollar Threshold Works Each Year
Social Security sets a minimum earnings amount each January. In 2024, for example, you need to earn $1,550 in a single quarter to earn one work credit for that quarter. In 2025, that amount increased. The exact figure changes yearly because it is tied to the national average wage index.
You do not need to earn this amount every quarter — only in the quarters where you want to count a credit. If you earn $1,550 in January, you have earned your credit for the first quarter, even if you earn nothing for the rest of the year. If you earn $6,200 in January, you still have only one credit for that quarter; the extra money does not roll over or create additional credits.
Social Security publishes the current year's threshold on their website and in your annual Social Security statement. If you are unsure of the current amount, you can call Social Security at 1-800-772-1213 and ask what the threshold is for the current year.
Why Timing of Your Work Matters
The quarter in which you earn money determines when you get credit for it. A calendar quarter runs January through March (Q1), April through June (Q2), July through September (Q3), and October through December (Q4). If you earn $1,550 in February, that credit counts toward Q1. If you earn $1,550 in November, that credit counts toward Q4.
This matters because you can earn at most four credits per calendar year. If you work only during the summer months and earn $6,200 total, you might earn only one or two credits that year, depending on whether your earnings fall in one quarter or span two. If you work year-round and earn at least the threshold amount each quarter, you earn four credits that year — the maximum possible.
For people explore for SSDI, this timing can affect how long it takes to meet the work credit requirement. Someone who worked steadily for ten years will have 40 credits. Someone who worked the same total number of years but only during certain seasons may have far fewer.
Work Credits You Earned in the Past Still Count
Work credits do not expire. If you earned 30 credits between 2010 and 2015, then stopped working, those 30 credits remain on your Social Security record. If you later return to work and earn 10 more credits between 2024 and 2026, your total is 40 credits, and you meet the requirement for SSDI.
This is important if you have had periods of unemployment, illness, or caregiving. You do not have to earn all your work credits in recent years or in consecutive years. Social Security looks at your entire work history and counts every credit you have ever earned.
How This Affects Your SSDI Timeline
The 1+ Spasm rule means that the pattern of your work — not just the total amount you earned — determines how fast you build credits. Two people who earned the same total income over ten years might have different numbers of work credits if one worked steadily and the other worked in bursts.
For most people, working at least part-time in all four quarters of the year is the fastest route to 40 credits. If you work only seasonally or sporadically, you will earn fewer credits per year, which means you need to work longer to reach the SSDI threshold.
When you explore for SSDI, Social Security will pull your complete earnings record from the Social Security Administration database. They will count every quarter in which you earned at least the threshold amount, going back through your entire work history. You do not have to prove this yourself — Social Security has the record.
What Happens If You Have Not Earned Enough Credits Yet
If you explore for SSDI and have fewer than 40 credits (or 20 if you are under 31), Social Security will deny your process based on work credits alone, regardless of how severe your medical condition is. The medical review does not happen until you meet the work credit requirement.
This does not mean you cannot receive any benefits. You may be able to receive Supplemental Security Income (SSI), which has no work credit requirement but has strict income and asset limits. You can also continue working if you are able, earn more credits, and reapply for SSDI later. Some people reapply after a few more years of work and are approved the second time because they have now met the credit requirement.
Frequently Asked Questions
Can I earn more than one work credit in a single quarter?
No. The 1+ Spasm rule means you earn exactly one credit per quarter if you meet the earnings threshold, regardless of how much you earn above that amount. The maximum you can earn in any year is four credits.
Do I have to work the same amount every quarter?
No. You only need to earn the threshold amount in each quarter where you want to count a credit. You could earn $1,550 in January and nothing for the rest of the year and still have one credit for that year. You could earn $10,000 in one month and nothing else and still have only one credit.
What if I worked many years ago but not recently?
Those credits still count. Social Security counts work credits from your entire work history. If you earned 35 credits between 1995 and 2005, then stopped working, those 35 credits remain on your record. You would need only 5 more credits to reach 40, which you could earn by working part-time for about one year.
How do I know how many work credits I have right now?
You can view your work credits on your Social Security statement, which you can access online at ssa.gov by creating a my Social Security account. You can also call Social Security at 1-800-772-1213 and ask them to tell you your current work credit count.
Does the dollar threshold change every year?
Yes. Social Security adjusts the earnings threshold each January based on national wage trends. The amount usually increases slightly each year, but the increase is typically small. Social Security announces the new threshold in October or November of the previous year.