If California tried to withhold federal taxes, almost nothing would change for individual taxpayers, and almost everything would go wrong for the state. Californians pay federal income and payroll taxes directly to the IRS through their employers’ payroll systems or their own estimated payments, and the state government has no legal authority to intercept any of it. The narrow slice of money the state does control — employment taxes withheld from its own workforce, certain federal excise taxes, and required contributions to joint programs like Medi-Cal — could be withheld only at the cost of federal lawsuits, escalating penalties, personal criminal exposure for the officials signing the orders, and offsets against the $174.5 billion in federal funds flowing into the state budget.
What the State Actually Controls
The phrase “California stops paying federal taxes” collapses two very different things. Individual federal tax obligations run directly from each taxpayer to the IRS. Employers withhold income tax, Social Security, and Medicare from paychecks and remit those funds to the federal government. Self-employed workers send estimated payments on their own. Sacramento is not in the chain, and no state law can put it there.
What the state government controls is its own obligations as an employer and as a partner in federal-state programs. California employs roughly 230,000 workers, and like every employer in the country it must withhold and deposit federal employment taxes on their wages.1Internal Revenue Service. Government Entities and Their Federal Tax Obligations It collects certain federal fuel excise taxes and remits them. It makes required state contributions to Medi-Cal, California’s Medicaid program. Those payments are large in absolute terms, but they are a small fraction of the federal tax revenue coming out of the state, and the money flows in the opposite direction from the political rhetoric: federal funds account for roughly a third of California’s state budget.
Why the State Cannot Block Federal Tax Collection
The Constitution forecloses the direct version of this. The Supremacy Clause in Article VI makes federal law override conflicting state law, so no state statute or executive order can nullify a federal tax obligation.2LII / Legal Information Institute. Supremacy Clause The Sixteenth Amendment separately gives Congress the power to tax incomes “from whatever source derived, without apportionment among the several states.”3Cornell Law Institute. 16th Amendment The federal government collects from individuals on its own authority. It does not need California’s cooperation.
The courthouse door is also effectively closed. The Anti-Injunction Act prohibits suits that seek to restrain the assessment or collection of federal taxes.4Office of the Law Revision Counsel. 26 U.S. Code 7421 – Prohibition of Suits to Restrain Assessment or Collection The ordinary route for challenging a federal tax is to pay first and sue for a refund. States occasionally get slightly more room under precedent like South Carolina v. Regan, which allows a challenge when the state suffers a specific financial harm and has no other way to litigate. That exception is narrow, and a blanket refusal to remit would not fit it. It would look like defiance, not a legal challenge.
What California Could Legally Refuse
There is one real area of state leverage, and it is narrower than the headlines suggest. Under the anti-commandeering doctrine from New York v. United States (1992) and Printz v. United States (1997), the federal government cannot force state officials to administer or enforce federal programs.5LII / Legal Information Institute. Anti-Commandeering Doctrine – U.S. Constitution Annotated California could legally decline to lend state personnel or resources to IRS enforcement, audits, or data sharing. The legislature could prohibit state agencies from assisting federal tax collection beyond the state’s own obligations, in the same posture the state has taken on immigration enforcement.
Refusing voluntary cooperation is not the same as refusing to remit money the state is legally required to pay. The state as an employer must deposit the federal income tax, Social Security, and Medicare contributions it withholds from employee wages. That duty is not a cooperation question; it is a direct legal obligation, and the penalties for ignoring it are severe.
How the Federal Government Would Respond
The federal government’s most effective tool is money, not litigation. Federal funds flowing into California’s state budget total roughly $174.5 billion for the 2025–26 fiscal year, with about $119 billion of that going to Medi-Cal alone. Highway construction, K-12 education, higher education, and social services account for tens of billions more. If the state fell behind on amounts it owed, the Treasury Offset Program lets federal agencies withhold part or all of federal payments to satisfy a delinquent debt, and offsets continue until the debt plus interest and penalties is paid in full.6eCFR. 31 CFR 285.5 – Centralized Offset of Federal Payments to Collect Nontax Debts Owed to the United States
One constitutional guardrail limits how aggressively the federal government can retaliate. The Supreme Court held in NFIB v. Sebelius (2012) that Congress cannot threaten states with the complete loss of existing Medicaid funding to force compliance with new requirements, calling that a “gun to the head.” So the entire $119 billion in Medi-Cal money probably could not be yanked over, say, an excise tax dispute. Funding conditions have to be reasonably related to the program at issue. Within that limit, the latitude to offset specific debts against specific payments is still enormous, and the arithmetic runs against the state.
Alongside offsets, the IRS would start assessing penalties for failure to deposit employment taxes. The penalty begins at 2 percent of the underpayment for delays of five days or less, rises to 5 percent for six to fifteen days, hits 10 percent after fifteen days, and climbs to 15 percent if the taxes remain unpaid after the IRS sends a delinquency notice.7Office of the Law Revision Counsel. 26 U.S. Code 6656 – Failure to Make Deposit of Taxes Interest compounds daily on top of those penalties at the federal short-term rate plus three percentage points, which runs at 7 percent for the first quarter of 2026 and 6 percent for the second quarter.8Internal Revenue Service. Quarterly Interest Rates
Personal Liability for the Officials Who Would Carry It Out
This is the part of the plan that tends to collapse on contact with reality. The Trust Fund Recovery Penalty makes any “responsible person” who willfully fails to collect or pay over withheld taxes personally liable for the full unpaid amount.9Office of the Law Revision Counsel. 26 U.S. Code 6672 – Failure to Collect and Pay Over Tax, or Attempt to Evade or Defeat Tax The statute reaches “any person” responsible for the employer’s tax duties, and it does not exempt state officials. A state controller, a payroll director, or an agency head who followed an executive order to stop remitting withheld taxes could be personally on the hook for every unpaid dollar.
On top of civil liability, willful failure to collect or pay over tax is a federal felony punishable by up to five years in prison and a $10,000 fine.10Office of the Law Revision Counsel. 26 U.S. Code 7202 – Willful Failure to Collect or Pay Over Tax A governor can give the speech. The career official who would actually have to stop signing the checks faces financial ruin, a criminal record, and prison time. Finding enough willing hands at the operational level is a bigger obstacle than any legal theory.
Collateral Damage: Employees and Borrowing Costs
State employees would be caught in the middle. Because the IRS generally credits workers for the federal income tax and payroll tax shown on their W-2 even when the employer fails to deposit the money, individual employees would not immediately owe more at tax time.11Internal Revenue Service. Publication 15 (2026), (Circular E), Employer’s Tax Guide Social Security is a different story. If the state failed to remit its share of FICA taxes, the Social Security Administration might not credit affected workers’ earnings records correctly. The SSA can correct records when wages are missing or understated, but corrections take time, and workers nearing retirement could see benefit calculations delayed.12Social Security Administration. Correction of the Record of Your Earnings After the Time Limit Ends
Borrowing costs would take a hit as well. California is one of the largest municipal bond issuers in the country, and the tax-exempt status of those bonds keeps interest rates low. Taxable municipal bonds yield more than comparable tax-exempt bonds of the same issuer, in many cases by more than 50 percent, according to Moody’s.13Moody’s Investors Service. Losing Tax Exemption Would Increase Borrowing Costs, Market-Access Risks Even short of a formal loss of exemption, an open fiscal fight with Washington that put tens of billions in federal funding at risk would almost certainly trigger a credit rating review. A downgrade means higher interest on every new bond the state issues, which shows up as real money on every infrastructure project, school bond, and water system upgrade.
The Likely Sequence
Walk through the realistic chain of events. A governor signs an executive order telling state agencies to stop remitting certain federal payments. Within days, the Department of Justice sues under the Supremacy Clause and asks a federal court to compel compliance.2LII / Legal Information Institute. Supremacy Clause The IRS begins assessing failure-to-deposit penalties against the state as an employer.7Office of the Law Revision Counsel. 26 U.S. Code 6656 – Failure to Make Deposit of Taxes Treasury flags delinquent amounts for offset against upcoming federal disbursements.
Individual Californians keep paying their federal taxes exactly as before, because their obligations run straight to the IRS and have nothing to do with Sacramento.14Internal Revenue Service. Understanding Employment Taxes The state officials who signed off on nonpayment receive personal Trust Fund Recovery Penalty assessments and face potential felony exposure.10Office of the Law Revision Counsel. 26 U.S. Code 7202 – Willful Failure to Collect or Pay Over Tax A federal court issues an injunction within weeks. The state either complies and pays the accumulated penalties and interest, or watches federal offsets consume funding it needs for Medi-Cal, schools, and highways. With $174.5 billion in federal money flowing through the state budget, the leverage runs overwhelmingly one direction, which is why this threat has stayed rhetorical every time it has been raised.