Quick answer: the biggest delay risk beyond the 12–18 month norm is hesitation over authorizing more attorney time at DC's high rates, followed by a contested will and the separate estate tax process. Estimate your own timeline with the DC probate timeline calculator.
1. Cost hesitation, given DC's high attorney rates
2. A contested will
A formal objection to a will's validity moves the case out of standard administration and into contested proceedings before the Probate Division, adding real time before the case can proceed.
3. DC's separate estate tax process
For estates above the $4,988,400 exemption, the separate Form D-76 return, due 10 months after death, runs alongside the periodic accountings and can extend how long final closing takes, especially for a larger or more complex estate.
4. A missed or incomplete accounting
Because the Probate Division expects periodic accountings roughly every 9 to 12 months, a missed deadline or an incomplete filing can prompt a court inquiry, pushing the eventual closing date further out than the standard timeline would suggest.
A local probate attorney can review your estate — many offer a free consultation.