California S-Corp Tax Guide for Physicians

California S-Corporation Tax Overview

California treats S-Corporations differently than the federal government and differently than every other state. While the IRS taxes S-Corporations as pass-through entities with zero entity-level tax, California imposes two separate taxes on S-Corporations: a minimum $800 annual franchise tax and a 1.5 percent entity-level tax on net income. Combined with California's top personal income tax rate of 13.3 percent, California physicians face the highest state tax burden in the nation.

Last updated: May 2026

For independent contractor physicians earning $400,000 to $800,000 annually through a California S-Corporation, the total California state tax liability typically ranges from $50,000 to $120,000 annually, representing 12 to 15 percent of gross income before federal taxes are even considered. This creates enormous pressure to optimize every available deduction, manage income carefully across state lines, and plan strategically for potential relocation.

Last updated: May 2026

Despite the high cost, S-Corporation structure remains optimal for California physicians. The self-employment tax savings (approximately $15,000 to $30,000 annually depending on income) plus retirement plan access (Solo 401k, Cash Balance Plans) plus QBI deduction benefits outweigh the incremental California entity-level tax. But the California-specific complexity requires California-specific expertise.

Last updated: May 2026

The Double Tax Problem: $800 Franchise Tax Plus 1.5% Entity Tax

California is the only state that imposes both a minimum franchise tax and an entity-level income tax on S-Corporations. Understanding how these taxes interact and when they apply is critical for California physicians.

Last updated: May 2026

$800 Minimum Franchise Tax

Every California S-Corporation pays a minimum $800 annual franchise tax regardless of income, profit, or operational status. This tax is due for every year the entity exists, beginning with the second year of operation. Newly formed S-Corporations receive a one-year exemption, meaning the first tax year is free, but $800 is due for year two even if the entity generated zero income. Note that while the $800 minimum is waived for the first year, the S-Corporation is still subject to the 1.5 percent entity-level tax on any net income earned during that first year.

Last updated: May 2026

The $800 is a minimum. If the entity-level tax (1.5 percent of net income) exceeds $800, the entity-level tax applies instead. The S-Corporation never pays both. It pays the greater of $800 or 1.5 percent of net income.

Last updated: May 2026

1.5% Entity-Level Tax on Net Income

California imposes a 1.5 percent tax on the S-Corporation's net income. This is calculated on California-source net income after business deductions but before the income passes through to shareholders. For a physician S-Corporation, net income is roughly gross 1099 receipts minus business expenses (W-2 salary to the physician, retirement contributions, malpractice insurance, CME, professional fees, etc.).

Last updated: May 2026

Why This Matters for Strategic Planning

The 1.5 percent entity-level tax creates a strong incentive to maximize deductible expenses at the S-Corporation level. Every dollar of legitimate business expense saves 1.5 percent entity tax plus 9 to 13.3 percent personal tax plus 37 percent federal tax. A physician in the top California and federal brackets saves roughly 52 cents per dollar of deductible expense.

Last updated: May 2026

This drives aggressive retirement plan funding (Solo 401k contributions reduce net income subject to 1.5 percent tax), front-loading CME and equipment purchases before year-end, paying reasonable W-2 salary (wages are deductible at entity level), and careful documentation of all business expenses.

Last updated: May 2026

Doing Business in California: The $693,000 Threshold

Out-of-state physicians working in California frequently ask whether their S-Corporation must register with California and pay California taxes. The answer depends on whether the S-Corporation is "doing business" in California under Franchise Tax Board rules.

Last updated: May 2026

The Sales Threshold Test

An S-Corporation is doing business in California if its California-source sales, property, or payroll exceed specific thresholds. For most physician S-Corporations, the sales threshold is the only relevant test. The 2026 threshold (subject to annual inflation adjustment) is projected at $711,538 in California-source sales.

Last updated: May 2026

If a physician's S-Corporation generates more than $711,538 in California-source revenue (1099 income from work performed in California), the S-Corporation must register as a foreign entity with California, file California S-Corporation returns (Form 100S), and pay California franchise tax and entity-level tax.

Last updated: May 2026

If California-source revenue is below $711,538, the S-Corporation itself has no California filing obligation. However, the physician personally still owes California non-resident tax on the California-source income. The threshold determines entity registration, not personal tax filing.

Last updated: May 2026

The Property and Payroll Tests

Two additional tests can trigger doing business status even if sales are under the threshold. If the S-Corporation owns California real property exceeding 25 percent of total property value, it is doing business in California. If the S-Corporation pays California wages exceeding 25 percent of total compensation, it is doing business in California.

Last updated: May 2026

For independent contractor physicians, these tests rarely apply. The physician typically has no California real property and no California employees. The only relevant test is the sales threshold.

Last updated: May 2026

California Estimated Tax Payment Requirements

California requires estimated tax payments from both the S-Corporation (if doing business in California) and the individual physician (if earning California-source income). These are separate obligations with separate deadlines and separate penalty structures.

Last updated: May 2026

S-Corporation Estimated Payments

If the S-Corporation is doing business in California and expects to owe more than $800 in franchise tax, it must make quarterly estimated payments. The payments are based on the greater of 100 percent of prior year tax or 90 percent of current year tax. Most physician S-Corporations use the prior year safe harbor to avoid calculating current year estimates.

Last updated: May 2026

California S-Corporation estimated payments are due April 15, June 15, September 15, and January 15 (of the following year). These dates differ slightly from federal estimated payment dates, creating coordination complexity.

Last updated: May 2026

Personal Estimated Payments

The physician must make personal California estimated payments if expecting to owe more than $500 in California tax after withholding and credits. For physicians with significant California-source S-Corporation income, this threshold is always exceeded.

Last updated: May 2026

California personal estimated payments follow the same calendar as federal: April 15, June 15, September 15, January 15. However, California does not allow annualization the way the IRS does, meaning physicians with uneven quarterly income cannot easily adjust California estimates to match actual income timing.

Last updated: May 2026

Underpayment Penalties

California assesses underpayment penalties on both S-Corporation and personal returns if estimated payments are insufficient. The penalty rate is variable and compounds daily, typically ranging from 5 to 8 percent annually. For high-income physicians owing $50,000+ in California tax, underpayment penalties can reach $2,000 to $4,000 if estimates are materially short.

Last updated: May 2026

Employment Development Department (EDD) Compliance

California's Employment Development Department administers payroll taxes, unemployment insurance, and employment tax compliance. For S-Corporation owners paying themselves W-2 wages, EDD compliance is mandatory and strictly enforced.

Last updated: May 2026

Registration Requirements

Any S-Corporation paying California wages must register with EDD and obtain an employer account number. This applies even if the only employee is the physician-owner. Registration triggers quarterly payroll tax filings (Form DE-9) and annual reconciliation (Form DE-9C).

Last updated: May 2026

State Disability Insurance (SDI) and Personal Income Tax (PIT) Withholding

California requires withholding of State Disability Insurance (SDI) and Personal Income Tax (PIT) from W-2 wages. For 2026, there is no cap on wages subject to SDI tax. The SDI rate is 1.1 percent applied to all W-2 wages, regardless of amount. This is a significant recent change that materially impacts high-earning physicians paying themselves substantial W-2 salaries. A physician taking $240,000 in W-2 salary pays $2,640 in SDI ($240,000 × 1.1 percent), an amount that would have been capped at lower wage levels in prior years.

Last updated: May 2026

PIT withholding is based on the employee's W-4 and income level, typically 5 to 10 percent for physicians.

Last updated: May 2026

S-Corporation owners sometimes attempt to avoid SDI by classifying themselves as corporate officers exempt from SDI. This position is legally tenuous and frequently challenged in EDD audits. Conservative practice is to pay SDI on reasonable compensation wages.

Last updated: May 2026

Unemployment Insurance (UI) and Employment Training Tax (ETT)

Employers pay UI tax on the first $7,000 of each employee's wages. New employers pay 3.4 percent. Established employers pay a variable rate based on claims history. For single-owner S-Corporations where the physician never files unemployment claims, the rate eventually drops to the minimum (currently around 1.5 percent).

Last updated: May 2026

Employment Training Tax is 0.1 percent on the first $7,000 of wages. This is a small but mandatory additional tax.

Last updated: May 2026

EDD Audits

EDD conducts random audits and targeted audits based on specific risk factors. Common audit triggers include independent contractor reclassification (are your 1099 contractors actually employees?), officer compensation (is the W-2 salary reasonable or artificially low?), and SDI exemption claims (are you legitimately exempt or improperly avoiding the tax?).

Last updated: May 2026

For physician S-Corporations with no employees other than the owner, EDD audits typically focus on whether the physician's W-2 salary is reasonable. If EDD determines the salary is too low relative to distributions, they can reclassify distributions as wages and assess back taxes plus penalties.

Last updated: May 2026

Multi-State Tax Planning for California Physicians

Many California physicians work outside California, creating multi-state tax obligations. California's aggressive enforcement and high rates make multi-state planning particularly important.

Last updated: May 2026

California Resident Working in Other States

California residents are taxed on worldwide income regardless of where it is earned. A California resident physician working locum contracts in Nevada, Arizona, or Texas must still pay California tax on that income. California allows a credit for taxes paid to other states, but only to the extent of California's rate.

Last updated: May 2026

Exit Strategies: Leaving California

Many high-income California physicians consider relocating to lower-tax states. The tax savings are substantial. A physician earning $700,000 in California pays roughly $75,000 in state taxes. The same physician in Nevada, Texas, or Florida pays zero. Annual savings: $75,000, compounding to $750,000 over ten years.

Last updated: May 2026

Establishing Domicile in a New State

Changing tax residency requires changing domicile, which California defines as the place where you intend to remain permanently. Intent is determined by facts and circumstances including where you live, where you work, where your family lives, where you own property, where you vote, where you register vehicles, where you maintain professional licenses, where you hold bank accounts, and where you spend time.

Last updated: May 2026

Safe exit from California requires establishing clear domicile in the new state. This means obtaining a driver's license in the new state, registering to vote there, purchasing or renting a primary residence there, spending more than 183 days per year there, moving financial accounts there, and severing as many California connections as practical.

Last updated: May 2026

The 9-Month Rule and Year-of-Move Planning

California taxes residents on a pro-rata basis during the year of move. If a physician moves to Nevada on July 1, they are a California resident for the first six months and a Nevada resident for the last six months. Income is apportioned accordingly.

Last updated: May 2026

However, if the physician can demonstrate they were a California resident for fewer than 9 months during the year and were present in California for fewer than 183 days, they may be able to allocate all income earned after the move date as non-California source income. This requires meticulous day counting and documentation.

Last updated: May 2026

Continuing to Work in California After Relocation

Relocating to Nevada but continuing to work California locum contracts creates ongoing California tax obligations. The income sourced to California (where services are performed) remains subject to California non-resident tax regardless of Nevada residency. However, the Nevada-source income escapes California taxation, and the physician avoids the 1.5 percent S-Corporation entity tax by operating the entity from Nevada.

Last updated: May 2026