Read the procedural safeguards document.
https://osse.dc.gov/sites/default/files/dc/sites/osse/publication/attachments/Part%20B%20Procedural%20Safeguards.pdf
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The LEA must give you copies of certain documents before or after an IEP team meeting takes place. No
fewer than 5 business days before an IEP team meeting where the team will discuss an IEP or eligibility
for special education, the LEA must give you an accessible copy of any evaluation, assessment, report,
data chart, or other document that will be discussed at the meeting. If the meeting is scheduled fewer
than 5 business days before it is to occur, the LEA must give you these documents at least 24 hours
before the IEP meeting.
No later than 5 business days after an IEP meeting at which a new or amended IEP has been agreed
upon, the LEA must give you a copy of the IEP. If the IEP has not been completed by the 5th business day,
or the LEA needs additional time to translate the document for you into another language as may be
required by the D.C. Language Access Act (D.C. Code ยง 2-1931 et seq.), the LEA must give you a copy of
the latest available draft IEP and a final copy when it is completed. The LEA must give you the final copy
within 15 business days of the meeting at which the IEP was agreed upon.
There isn't a formal deadline for you to return comments after the IEP meeting because the final IEP is supposed to be a working draft during the meeting and reflect your input.
I usually return it to them within 48 hours -- and send an email telling them that's how long it will be.