Read the reason, not just the heading

Letter 916C is used for a claim that the IRS does not consider, including incomplete or rejected claims. IRS procedures require the letter to explain why the claim is not being considered.

Find the missing piece

Compare the explanation with your original claim, attachments, and any earlier request for information. The issue may require more than sending the same papers again. If you believe the requested material was already supplied, keep its delivery evidence with your review notes.

Do not assume a new deadline

Ask a qualified tax professional to review any filing or litigation deadlines tied to the underlying claim. A new piece of correspondence should not be treated as proof that an earlier deadline restarted. Bring prior disallowance letters and envelopes to that review, not just Letter 916C.