We were awarded a 5 year IDIQ to a Joint Venture. The managing partner is attempting to submit a final closeout invoice which incorporates audited final indirect rate adjustments from the various partners. This final invoice is under a CPFF task order (s), and totals approx. $100k. The Govt Agency is basically saying "sorry charlie", you should have informed us of this adjsutment sooner (i.e., that the task order ceiling would be exceeded). In fact, they say, we should have informed them in the last 75% letter under the limitiation of cost clause. We have not seen final indirect rate adjustments being addressed in a 75% letter. Is this place for us to notify the Govt of our expectation that our audited indirect rates will be greater than anticipated thus, we will exceed the Task Order ceiling?. Final audited rates are an unknown for several years so how can this matter be addressed in a final 75% letter ?. Especially, when 5 JV partners are involved? We feel the Agency should pay the final indirect rate adjustment invoice under these CPFF task orders ---there was no ceiling on the indirect rates in IDIQ. Who has the stronger case? the Agency or us?