When the Tax Year Closes: Which Decisions End December 31 and Which Stay Open Until You File

Steve Perry

Published on: 27/10/2026

Before you file your 2026 return, December 31 decides much of what it will say. See which tax decisions close at year end, which stay open until filing, and why waiting costs options.

December 31 tax deadlineyear-end tax planning 2026tax decisions before December 31IRS information matchingCP2000 notice401(k) deadline December 31required minimum distribution deadlineequipment placed in service December 31bonus depreciation 2026Section 179 limit 2026IRA contribution deadline 2026HSA contribution deadlineSEP IRA deadlinetax planning for business ownerstax planning for high net worth

October 15 Superseding Return Deadline: Rewrite Your Return Before You Amend

Steve Perry

Published on: 14/10/2026

Before October 15, a superseding return replaces your extended 2025 return. After that, fixes become amendments, and some depreciation and expensing elections may be lost.

superseding returnOctober 15 deadlineextended tax returnamended returnForm 1040-Xrewrite tax returnbonus depreciation electionelect out of bonus depreciationde minimis safe harbor electionsection 179 amended returnlate depreciation electionletter rulingIRS matchingIRS noticetax planning for business ownershigh net worth tax planningSteve Perry EABooks Taxes & MoreIRS resolution Atlanta