Sep
Abbreviation with 3 meanings
| Stands for | September |
|---|---|
| Meanings | 3 |
| Categories | Units & Measurements, Government & Politics, Law & Legal |
| Also written | SEP |
Sep has three meanings. The most common are September (month) and Special enrollment period (public program); it can also stand for Standard-essential patent.
Meanings of Sep at a glance
| # | Sep stands for | Context |
|---|---|---|
| 1 | September | Units & Measurements › Month |
| 2 | Special enrollment period | Government & Politics › Public Program |
| 3 | Standard-essential patent | Law & Legal › Intellectual Property |
1. September
Units & Measurements · Month Abbreviations
Ninth month of the year, with 30 days, named from Latin septem, seven, because it was the seventh month of the early Roman calendar that began in March. Sep is the three-letter form used in ISO-style and software date formats.
Example: Backup completed 14-Sep-2026 03:00 UTC.
Programming languages and international date formats almost always use Sep, generated by patterns such as MMM, while AP style prefers Sept. British publications use both. The September equinox, around September 22 or 23, begins autumn in the Northern Hemisphere and spring in the Southern.
2. Special enrollment period (SEP)
Government & Politics · Public Program Abbreviations · also used in medicine
Window outside the annual open enrollment period during which a person can sign up for or change health coverage after a qualifying life event, such as losing other coverage, marriage, birth or adoption of a child, or moving.
Example: Losing her job's insurance qualified her for a 60-day SEP on the marketplace.
For ACA marketplace plans, most special enrollment periods last 60 days from the event, and documentation may be required. Medicare has its own special enrollment periods, for example when someone stops working and loses employer coverage after age 65. In retirement savings, SEP also means a Simplified Employee Pension IRA.
3. Standard-essential patent (SEP)
Law & Legal · Intellectual Property Abbreviations
Patent claiming an invention that must be used to comply with a technical standard, such as 4G and 5G cellular, Wi-Fi, Bluetooth or video compression. Owners usually commit to standard-setting organizations to license SEPs on FRAND terms.
Example: Phone makers must license thousands of SEPs to sell 5G devices.
Disputes over SEP royalties fuel litigation worldwide, and courts in the UK, Germany, China and the US have set or reviewed global rates, as in Unwired Planet v Huawei [2020] UKSC 37. Holders seeking injunctions in Europe face competition-law limits following the CJEU's Huawei v ZTE judgment (2015).
Related abbreviations
More month abbreviations
See all 12 month abbreviations →
More public program abbreviations
- PWA – Public Works Administration
- REA – Rural Electrification Administration
- SAI – Student Aid Index
- SAVE – Saving on a Valuable Education plan
- SGA – Substantial gainful activity
- SNAP – Supplemental Nutrition Assistance Program
- SSDI – Social Security Disability Insurance
- SSI – Supplemental Security Income
See all 65 public program abbreviations →
This entry is for general education and is not legal advice. Abbreviation use varies between institutions; always confirm in context.