D.C. Revenue Forecast Rises, but Federal Challenge to Local Tax Decoupling Keeps Filers Uncertain

Revenue outlook improves even as tax rules remain unsettled

Washington, D.C.’s latest revenue outlook shows stronger-than-anticipated collections in key categories, but the District’s financial planning is being complicated by an unresolved dispute over whether local tax law can diverge from recently enacted federal tax changes.

The uncertainty centers on the District’s decision to “decouple” parts of its income and business tax system from a federal package enacted in 2025, a move adopted by the D.C. Council through emergency and follow-on temporary legislation. Decoupling is designed to prevent certain federal tax reductions from automatically lowering District taxable income and, by extension, District revenue.

What the District changed, and why it matters

The local legislation addressed a range of individual and business provisions that would otherwise flow through from the federal code, including adjustments tied to the standard deduction and multiple new or expanded deductions and exclusions affecting household and wage income. On the business side, the District’s approach also targeted provisions affecting the timing and size of deductions for research and experimental expenses, interest expense limitations, and certain depreciation-related rules.

District fiscal staff have treated the decoupling decision as a material budget item because conformity with the federal changes was projected to reduce local revenue over the financial plan period. The Council paired portions of the tax package with expansions of local credits, including changes affecting the Earned Income Tax Credit and a local child tax credit structure.

Congressional action drives the current confusion

Because the District operates under congressional review authority for its legislation, the local tax changes became the subject of federal efforts to block or reverse them. That created a real-time administrative challenge: residents and businesses filing District returns must know which set of rules applies, while the government must estimate cash flow and year-end collections with rules potentially changing midstream.

In late February 2026, the District’s chief financial officer publicly quantified the budget exposure from the dispute, warning that unresolved federal action could translate into a measurable revenue hit. The estimate highlighted a potential $180 million impact tied to ongoing “uncertainty” over whether the District will be able to continue collecting taxes under the decoupled framework.

How taxpayers could be affected this filing season

For filers, the practical issue is whether certain categories of income that may be treated more favorably under federal rules—such as income linked to newly created federal deductions—remain taxable under District rules. If the governing framework shifts, residents and employers could face amended filings, revised withholding guidance, or administrative delays as systems are updated.

• Residents could see differences between federal and District taxable income calculations.
• Businesses could face changes to deductions and expense timing used to compute District tax liability.
• District budget officials must plan for potential cash-flow disruptions if collections timing changes.

The dispute leaves the District balancing two simultaneous realities: recent revenue strength in collections data and a policy-driven risk that key tax assumptions may not hold through the full budget cycle.

What happens next

The next steps depend on federal action and the District’s response through additional local legislation, administrative guidance, or both. Until the legal and legislative questions are resolved, the CFO’s revenue estimates are likely to continue reflecting both improved near-term performance and a distinct downside risk tied to the decoupling fight.