COB
Abbreviation with 3 meanings
| Stands for | Close of business |
|---|---|
| Meanings | 3 |
| Categories | Business & Finance, Medical, Military |
COB has three meanings. The most common are Close of business (management & strategy) and Coordination of benefits (health insurance); it can also stand for Chief of the boat.
Meanings of COB at a glance
| # | COB stands for | Context |
|---|---|---|
| 1 | Close of business | Business & Finance › Management & Strategy |
| 2 | Coordination of benefits | Medical › Health Insurance |
| 3 | Chief of the boat | Military › Military Term |
1. Close of business
Business & Finance · Management & Strategy Abbreviations · also used in general use
End of the working day, used as a deadline in business, legal and government correspondence and generally meaning about 5 p.m. local time on the stated day. Banks and trading firms use the term for the cutoff after which transactions are processed on the next business day.
Example: Please return the signed amendment by COB Thursday, March 6.
Interchangeable with EOD and EOB in most offices, though COB is more common in formal, financial and government writing. Contracts that use "close of business" often define it precisely, for example as 5:00 p.m. New York time, because the phrase is otherwise ambiguous. In US health insurance, COB can also stand for coordination of benefits.
2. Coordination of benefits
Medical · Health Insurance Abbreviations
Rules deciding which health plan pays first when a person has more than one source of coverage, such as two employer plans, Medicare plus employer coverage, or auto insurance after an accident. The primary plan pays first, and the secondary plan may cover some remaining costs.
Example: COB update needed: claims were denied until I confirmed my spouse's plan is primary.
For children covered by both parents, most plans use the "birthday rule": the plan of the parent whose birthday falls earlier in the calendar year is primary. Medicare Secondary Payer rules determine when Medicare pays second. Insurers send periodic COB questionnaires, and unanswered ones can stall claims.
3. Chief of the boat
Military · Military Term Abbreviations
Senior enlisted sailor aboard a submarine, a master or senior chief who advises the commanding officer on crew matters, manages the watch bill and enforces standards.
Example: Talk to the COB if you want to swap your watch section.
The title reflects the Navy tradition of calling submarines "boats." Surface ships and other commands use the title command master chief for the equivalent role. In business usage, COB means close of business.
Related abbreviations
More management & strategy abbreviations
- C-level – Chief level (executive rank)
- C-suite – Chief executive suite (senior executives with chief titles)
- CAPA – Corrective and preventive action
- CI – Continuous improvement
- CoE – Center of excellence
- CSF – Critical success factor
- CSR – Corporate social responsibility
- CTQ – Critical to quality
See all 92 management & strategy abbreviations →
More health insurance abbreviations
- CDM – Charge description master (chargemaster)
- CHIP – Children's Health Insurance Program
- CMS – Centers for Medicare & Medicaid Services
- CMS-1500 – CMS-1500 claim form
- COBRA – Consolidated Omnibus Budget Reconciliation Act
- CPT – Current Procedural Terminology
- DCFSA – Dependent care flexible spending account
- DRG – Diagnosis-related group
See all 107 health insurance abbreviations →
This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.