California SDI vs. Private Short-Term Disability Insurance: What’s the Difference?

By Michael Steiner | SDI Advisor

If you work for a California employer, you are covered by some form of short-term disability insurance. That much is true for almost every California employee. But which program covers you — the state’s SDI program or your employer’s private plan — and what the difference means for how you file, how much you receive, and what rules apply to your claim are questions most workers have never thought about until the moment they need to file.

This post explains the landscape clearly: how California SDI works, what employer-sponsored private disability plans are and how they differ, what a Voluntary Plan is and why it matters, how sick pay and supplemental employer benefits interact with your claim, and what the taxability rules look like for each type of plan.

By the end, you’ll know which program covers you and exactly what to do when you need to use it.

California SDI: The Foundation

California State Disability Insurance is the baseline program. It is a mandatory program funded through the CASDI payroll deduction — 1.3% of your wages in 2026, withheld from every paycheck with no cap — and administered by the California EDD. Almost every California worker with CASDI on their pay stub is covered.

What SDI provides:

Wage replacement of 70% to 90% of prior wages
Maximum weekly benefit of $1,765 in 2026
Up to 52 weeks of benefits per claim
7-day non-payable waiting period (benefits start on day 8)
Coverage for non-work-related illness, injury, pregnancy, and mental health conditions including depression, anxiety, and PTSD
Claims filed directly with the EDD through SDI Online at edd.ca.gov

SDI is the program most Californians will interact with directly. It is automatic, state-administered, and doesn’t require any enrollment decision on your part — you’ve been paying into it with every paycheck.

Our complete guide to SDI eligibility →

The Three Types of Private Short-Term Disability Coverage in California

Not all California workers are covered by the standard state SDI program. Some are covered by private alternatives, and some have supplemental coverage on top of SDI. Understanding which category applies to you is the first step.

Type 1: California Voluntary Plan (VP / VDI)

Some employers opt out of the standard state SDI program entirely and offer an EDD-approved Voluntary Plan (also called VDI — Voluntary Disability Insurance) as a replacement.

A Voluntary Plan is not optional in the sense that you can choose not to be covered — it replaces state SDI for the entire employee group. It is, however, subject to strict state rules:

It must provide at least the same benefits as state SDI in every respect
It must offer at least one benefit that is better than the state plan
It cannot cost employees more than the state SDI rate
It must be approved by the EDD before taking effect
A majority of employees must consent to the plan

In practice, Voluntary Plans often provide richer benefits than state SDI — higher wage replacement percentages, shorter waiting periods, or higher maximum weekly benefits. Large employers like universities, technology companies, and corporations frequently offer Voluntary Plans.

If you’re covered by a Voluntary Plan: You do NOT file your disability claim with the EDD. You file with your employer’s HR department or the plan’s third-party administrator (often an insurance company like MetLife, Sedgwick, Lincoln Financial, or NYL). The process is entirely separate from the EDD’s SDI Online system.

How to know if you have a Voluntary Plan: Check your pay stub. If it shows a deduction labeled “VPDI,” “VDI,” or something other than “CASDI,” you may be covered by a Voluntary Plan. The most reliable way to confirm is to ask your HR department directly.

Type 2: Supplemental Employer STD on Top of SDI

Some employers participate in the standard state SDI program — meaning CASDI is withheld from your paychecks and you file claims with the EDD — and also offer a separate, supplemental short-term disability benefit through a private insurer.

This supplemental STD is designed to fill the gap between what SDI pays and your full salary. For example, SDI might pay 80% of your wages, and your employer’s supplemental STD might pay an additional 15% to bring your total replacement closer to 95% or 100%.

How these interact: In most cases, you file for SDI first, and the supplemental STD pays the difference up to the combined maximum. The private insurance carrier typically offsets its payment by the SDI benefit you’re receiving — you don’t generally receive full benefits from both sources simultaneously.

How to know if you have supplemental STD: Check your employee benefits summary or ask HR whether your company offers supplemental disability coverage beyond state SDI.

Type 3: Individually Purchased Private Disability Insurance

Some workers purchase their own private disability insurance policies independently — not through an employer. These are individual contracts with private insurance companies, governed entirely by the policy terms rather than California law (beyond general insurance regulations).

Individual policies vary widely in their definitions of disability, benefit amounts, elimination periods (the private-insurance equivalent of waiting periods), and duration. They are completely separate from the state SDI system. You file claims with the insurance company directly, not the EDD.

Individual private disability policies are most common among higher earners, professionals, self-employed individuals who’ve set up their own coverage, or people who want protection beyond what any employer-sponsored plan provides.

Side-by-Side Comparison: State SDI vs. Voluntary Plan vs. Supplemental STD

	State SDI	Voluntary Plan (VP)	Supplemental Employer STD
Who administers it	California EDD	Employer / TPA	Private insurance carrier
Where you file	SDI Online (edd.ca.gov)	HR / employer portal	Insurance carrier directly
Benefit amount	70–90% of wages, up to $1,765/wk	At least equal to SDI; often better	Varies — fills gap to full pay
Maximum duration	52 weeks	At least 52 weeks; often same	Varies by plan (often 6–26 weeks)
Waiting period	7 days	At least same as SDI; often shorter	Varies by plan
Mental health qualifies?	Yes	Yes (required to match SDI)	Depends on plan terms
Funded by	Employee payroll deduction (1.3%)	Employee contribution (≤ state rate)	Employer and/or employee premiums
Taxable?	Generally no	Generally no (employee-funded)	Depends on who paid premiums
After leaving employer	Base period wages remain valid	Coverage ends with employment	Coverage ends with employment

How Sick Pay Interacts With SDI

This is one of the most practically important — and least understood — aspects of California SDI. How your employer’s sick leave or PTO interacts with your SDI claim affects how much you actually receive.

The general rule: If your employer continues to pay your full salary through sick leave, PTO, or a salary continuation policy, SDI benefits may be reduced or eliminated entirely. SDI is designed to replace lost wages, and if you’re not losing wages, the EDD may determine you have no wage loss to compensate.

The vacation-only exception: If you’re receiving purely accrued vacation pay while on disability, SDI benefits are generally not reduced. The EDD treats vacation as a separate, already-earned benefit rather than a salary continuation.

The practical implication: Many employers require you to use sick time or PTO before or concurrently with SDI. In that case, the employer may “integrate” your sick pay with SDI so that your total income doesn’t exceed 100% of your regular wages. For example:

SDI pays 85% of your wages
Your employer advances sick time equal to 15% of your wages
Combined, you receive 100% of your normal pay
Once sick time is exhausted, SDI continues alone at 85%

If your employer tops up your pay above 100% of your regular wages using sick pay, SDI benefits may be reduced. If the combination brings you to exactly 100%, SDI is generally unaffected.

What to do: Talk to your HR department before your leave begins to understand exactly how sick pay will interact with your SDI claim. Ask specifically: “Will my sick pay reduce my SDI benefits, and how is that calculated?” The answer varies significantly by employer policy.

Taxability: State SDI vs. Private Plans

Taxes are another area where SDI and private disability plans differ meaningfully.

State SDI Tax Treatment

California SDI benefits are generally not taxable at the state or federal level. There are narrow exceptions — most notably, if SDI is paid as a substitute for unemployment benefits, the substituted portion may be federally taxable. But for the vast majority of disability claimants, SDI benefits are tax-free income.

Our full guide to SDI taxability →

Voluntary Plan Tax Treatment

Benefits from a state-approved Voluntary Plan are generally treated the same as state SDI — not taxable at the state or federal level — because they are funded through employee payroll deductions made with after-tax dollars, just like state SDI.

However, tax treatment of Voluntary Plan benefits can become complicated depending on how your employer structured the plan. Some VP benefits are reported on W-2s, creating confusion about whether they’re taxable. If you receive Voluntary Plan benefits and are unsure about the tax treatment, consult a tax professional — don’t assume.

Supplemental Employer STD Tax Treatment

This is where taxability gets genuinely complex, and where the answer matters most financially:

If your employer paid the premiums: Benefits from employer-paid STD policies are generally federally taxable as ordinary income. The IRS treats these benefits like wages.

If you paid the premiums with after-tax dollars: Benefits are generally not taxable — you already paid tax on the money used to fund the coverage.

If premiums were split or paid pre-tax: Partial taxation may apply, calculated proportionally.

This distinction — who paid the premiums, and with what type of dollars — is the most important tax question with private STD policies. Check with your HR department to understand how your employer’s plan is structured.

Mental Health Claims: Does the Private Plan Match SDI’s Coverage?

For workers dealing with depression, anxiety, PTSD, or other mental health conditions, one important question is whether a Voluntary Plan or supplemental STD policy covers mental health the same way state SDI does.

California Voluntary Plans: By law, a Voluntary Plan must provide coverage at least equal to state SDI in all respects. Since state SDI explicitly covers mental health conditions — depression, anxiety, PTSD, and other clinically diagnosed conditions that prevent you from working — your employer’s Voluntary Plan must also cover them. A VP cannot exclude mental health while state SDI covers it.

Supplemental employer STD policies: These are governed by the specific policy terms, which vary by insurer and employer. Some policies fully mirror SDI’s mental health coverage. Others may include limitations such as:

Mental health benefit caps: Some policies limit mental health claims to a shorter duration than physical claims (e.g., 12 weeks maximum for mental health vs. 26 weeks for physical conditions)
Exclusions for pre-existing conditions: If your depression or anxiety existed before your coverage began, benefits may be limited or excluded during an initial period
Own-occupation vs. any-occupation definitions: Some policies apply a narrower disability definition for mental health claims than for physical ones

What to do: Pull out your Summary Plan Description (SPD) or policy documents and look for the mental health benefit provisions specifically. If mental health is limited or excluded in your private STD policy, state SDI may still be available separately — or simultaneously, if your employer’s plan doesn’t fully substitute for state SDI.

What Happens When You Leave Your Employer

This is a critical and often overlooked difference between state SDI and private employer plans.

State SDI: When you leave an employer, your SDI eligibility based on past wages doesn’t disappear. Your base period — the qualifying 12-month window of past earnings — continues to exist as long as it falls within 5 to 18 months of when your disability begins. This means you can file for SDI after leaving employment, as long as your disability began while you were employed or while you were actively looking for work, and your base period wages meet the $300 minimum.

Voluntary Plans and supplemental STD: These are employer-tied benefits. When your employment ends, your coverage under these plans generally ends too. A disability that begins after your last day of work typically won’t be covered by your former employer’s private plan.

This difference matters enormously for anyone who was laid off or fired and then develops a disabling mental health condition — or whose existing condition worsens after job loss. State SDI may still be available through prior wages. Your former employer’s private plan almost certainly is not.

Our guide to SDI after a layoff →

Step One: Figure Out Which Plan Covers You

Before you do anything else, you need to know which type of coverage applies to you. Here’s how to find out:

Check your most recent pay stub. Look at the deductions section:

If you see “CASDI” — you’re covered by state SDI and file with the EDD
If you see “VPDI,” “VDI,” or a similar code — you may be covered by a Voluntary Plan; confirm with HR
If you see a separate line for a disability insurance premium — you may have supplemental STD on top of SDI

Ask your HR department directly. The most reliable source. Ask: “If I needed to file a disability claim, would I file with the EDD or through a company plan? And do we have any supplemental disability coverage beyond state SDI?”

Check your benefits enrollment materials. Your annual benefits guide or Summary Plan Description (SPD) will describe what disability coverage exists and who administers it.

Filing Under Each Type of Plan

State SDI: File online at edd.ca.gov through SDI Online. Have your Claim ID ready for your provider to submit the medical certification. Process typically takes about two weeks from a complete claim. Step-by-step application guide →

Voluntary Plan: Contact your HR department or the plan’s third-party administrator. Do not file with the EDD — your claim routes through the employer’s system. The TPA (MetLife, Sedgwick, Lincoln Financial, or whoever your employer uses) handles the review and payment.

Supplemental employer STD: File the supplemental claim with the insurance carrier. Often your employer or HR initiates this process when you report your leave. The supplemental carrier coordinates with the EDD regarding your concurrent SDI benefits.

Individual private policy: File directly with the insurance company according to the claim procedures in your policy. Completely separate from the EDD.

Common Scenarios and What to Do

“I have CASDI on my pay stub and my company also offers supplemental disability through MetLife. Which do I file first?”

File SDI with the EDD first — the supplemental carrier typically needs your SDI award information to calculate their payment. Your HR department can walk you through the coordination process for your specific plan.

“My pay stub shows ‘VPDI’ instead of ‘CASDI.’ Does that mean I can’t get SDI?”

If your employer has an approved Voluntary Plan (VPDI), that plan replaces state SDI for your claim. You are not eligible for state SDI benefits for the same period covered by the VP — but you are covered by the VP, which must provide at least equivalent benefits. File with your employer’s VP administrator, not the EDD.

“I was laid off last month and just received a diagnosis of severe depression. My former employer had a Voluntary Plan. Can I use it?”

Almost certainly not. Voluntary Plans are employer-tied — coverage ends with employment. However, state SDI may be available if your prior employment wages fall within the base period window. Contact us or review your base period eligibility carefully. Base period guide →

“My employer’s STD policy has a 12-week cap on mental health claims. Will SDI cover me after that?”

If your employer’s STD is supplemental to state SDI (not a Voluntary Plan replacement), yes — SDI can continue after the STD benefit exhausts, up to 52 weeks total, as long as your disability continues and your provider keeps certifying it. Confirm with your employer whether your STD is supplemental to or a replacement for state SDI.

“My employer pays my STD premiums. Will my benefits be taxable?”

Employer-paid STD premiums generally mean the benefits are federally taxable. Consult a tax professional to understand the specific tax treatment based on how your plan is structured.

Frequently Asked Questions

How do I know if I have a Voluntary Plan or state SDI? Check your pay stub deduction label — “CASDI” means state SDI; “VPDI” or “VDI” typically indicates a Voluntary Plan. Your HR department can confirm definitively.

Can I have both a Voluntary Plan and state SDI? Not for the same claim period — the VP replaces state SDI for employees covered by it. However, if you work two jobs and one employer has state SDI while the other has a VP, both can cover you proportionally.

Do Voluntary Plans cover mental health? Yes — California law requires Voluntary Plans to provide at least the same coverage as state SDI, which explicitly includes mental health conditions.

Does private STD reduce my SDI benefits? If the private STD is a Voluntary Plan that replaces SDI, you receive benefits from the VP, not from state SDI. If the private STD is supplemental to SDI, the carrier typically offsets its payment by your SDI benefit so that combined benefits don’t exceed your regular wages.

Are state SDI benefits taxable? Generally no — state SDI disability benefits are not taxable federally or at the California state level in most circumstances.

Will my private STD benefits be taxable? Depends on who paid the premiums. Employer-paid premiums → generally taxable. Employee-paid with after-tax dollars → generally not taxable.

What happens to my private STD coverage if I’m terminated? Coverage generally ends with employment. State SDI eligibility based on your prior base period wages may still exist independently — check your base period window.

The Bottom Line

The landscape of California disability coverage has three distinct layers: the mandatory state SDI program, Voluntary Plans that some employers use as a replacement, and supplemental employer STD or individual policies that add coverage on top. Understanding which layer covers you determines where you file, what rules apply, how much you’ll receive, and what happens if your employment ends.

For most California workers — those with CASDI on their pay stubs who file with the EDD — the state SDI program is their program. For workers with Voluntary Plans, the process is handled through the employer. For those with supplemental coverage, coordination with the EDD claim is the key.

If you have questions about your specific situation — particularly if you’re dealing with depression, anxiety, or another mental health condition — reaching out for a free consultation is the fastest way to understand exactly which program applies to you and what your options are.

We Help With California SDI

SDI Advisor specializes in California State Disability Insurance claims for people dealing with depression, anxiety, PTSD, and other mental health conditions. We work on a contingency basis — no upfront cost, payment only if your claim is approved.

We do not administer Voluntary Plans or private STD policies. For questions about your employer’s Voluntary Plan or private STD, contact your HR department or the plan’s third-party administrator.

Contact us for a free California SDI consultation →