An employment agreement extension is a contract between an employer and employee that extends the term of the original contract agreements. For a sample release used in the employment context, see.LETTER 5 - Temporary Contract – extension of temporary employment. (insert today's date here). Ending a working relationship with an independent contractor requires you to write an effective termination letter. Discover 7 different employment verification letter templates with different details for proof of employment or future job opportunities. An extension and modification agreement is an addendum added to an existing contract that extends the terms and makes certain changes as outlined within. An alphabetical-by-topic list is provided below containing information and downloadable PDF forms, when available, or links to external resources. File both forms at the location specified for the other application or petition. For example, if you are filing Form I-765 with Form I-539 or Form I-485.