In the same situation presented by GOVCO (commercial item, sole source, IDIQ that allows for FFP and LH orders), I have heard people argue that since you are awarding an IDIQ contract, that (IDIQ) is your contract type. They essentially argue that the type of order you issue (FFP or LH) is irrelevant and any regulations addressing FFP or LH contracts (in this case, FAR 12.207() is not applicable to IDIQ contracts. As "support" for their argument, they state that FAR Part 16 is entitled "Contract Type" and Indefinite Quantity contracts are their own contract type, separate from FFP, T&M/LH, and CR.
I do not agree with this argument. Regardless of the inclusion of Indefinite Quantity contracts in FAR Part 16 - and thus the argument that it is its own contract type - an Indefinite Quantity contract cannot exist w/o one or more pricing arrangements (i.e., FP, CR, T&M/LH). In fact, FAR 16.501-2© specifically says "Indefinite-delivery contracts may provide for any appropriate cost or pricing arrangement under PAR 16."
All of this to say that I'd like to know if the WIFCON community thinks the following argument is valid: an IDIQ contract is its own contract type, and therefore rules that apply to T&M/LH contract types don't apply to an IDIQ contract or the T&M/LH orders that may be issued against it.