STD (short term disability) plans are normally only offered through an employer. Some employers provide STD coverage at little or no cost to you while others will make coverage available through payroll deduction.
Carriers such as AFLAC, Allstate, Colonial and others make STD coverage available in the workplace. In these situations you usually don't get to pick a plan from a different carrier.
There are only a couple of companies that sell private Short Term Disability Insurance. Mutual of Omaha is one, and Assurity Life also offers this product. Both are highly rated and respected companies. Most Short Term Disability Insurance is provided through an employer by the company of their choice.
Carriers such as AFLAC, Allstate, Colonial and others make STD coverage available in the workplace. In these situations you usually don't get to pick a plan from a different carrier.