Can additional scope and funding be added to a cost contract that the PoP has ended and all options have expired?
A contract change that is not within the general scope of the original contract in terms of type and amount of work, period of performance and manner of performance is considered an out-of-scope contract change and would violate the Competition in Contracting Act if not excepted from the Act or justified through the J&A process (see FAR 6.303).
If it is determined that the work is within the scope of the orignal contract (the additional work and extenstion were reasonably contemplated at the time of the original contract award [Freund v. U.S., 260 U.S. 60 (1922); Major Contracting Services, Inc., B-401472 (September 14, 2009)] you may be able to use the funding in the expired status to fund all or parts of the work considered an adjustment to an in-scope effort (seek assistance from your financial management with regard to this).
The orders and any extensions to that order must comply with the bona fide needs rule of federal appropriations law and FAR 32.703-3 (Contracts crossing fiscal years). Determine which clause(s) in the contract apply to your situation and read them to determine whether any allow you to provide additional time, costs, or work. (e.g. a government delay, a changes clause, etc.). FAR 17.204(a) provides that "the contract shall specify limits on the purchase of additional supplies or services, or the overall duration of the term of the contract, including any extension." Each order stands on its own and is basically its own mini-contract. You must read the basic order contract to determine whether it places limitations on the task order performance period, which clause in the contract applies to your contract situation, does it permit an extension and whether any consideration is called for (ask in this instance: is the extension required because the contractor failed to timely perform? If so, you should determine any appropriate amount of consideration)