California Workers' Compensation Calculator

The California Subsequent Injuries Benefit Trust Fund (SIBTF) — established under Labor Code §4751–§4755 — pays lifetime weekly benefits on top of what your employer's workers' comp insurance covers, when a pre-existing permanent disability combines with a new work injury to produce a severe combined disability. This is a separate claim against the State of California's trust fund, not against your employer or its insurer. You qualify when all three of the following are true: (1) you had a permanent partial disability or impairment before the new work injury occurred; (2) the new injury and the prior disability together produce a combined permanent disability of 70% or more; and (3) the new work injury alone rates at least 35% permanent disability — or, if the new injury affects the opposite hand, arm, foot, leg, or eye to the pre-existing disability, the threshold drops to just 5%. The prior disability can be industrial or non-industrial in origin; arthritis, a prior surgery, or a service-connected condition can all count as long as it was ratable as a permanent partial disability at the time of the new injury. You file a separate Application for Subsequent Injuries Fund Benefits at your local Workers' Compensation Appeals Board (WCAB), and benefit checks are issued by the SIBTF Claims Unit of the California DIR/DWC once the WCAB awards benefits. California courts apply a reasonable time standard to SIBTF filings — generally you should file as soon as your underlying permanent disability rating is finalized and it becomes clear you have a viable SIBTF claim.

The California Subsequent Injuries Benefit Trust Fund (SIBTF) Calculator concept works like this: SIBTF pays you the difference between (A) the weekly permanent disability benefits for your combined disability rating and (B) the weekly permanent disability benefits your employer's insurer pays for the new injury alone. The fund covers the gap — for life. Concrete example: A warehouse worker has a pre-existing 40% permanent disability from a prior knee injury. She then sustains a new back injury at work rated at 45% permanent disability on its own. Combined, the two disabilities interact to produce a 78% total permanent disability. Her employer's insurer is liable only for the 45% new-injury portion; the SIBTF covers the weekly payments attributable to the difference between 78% and 45% — paid every week for the rest of her life. At the extreme end, a combined rating of 100% total disability entitles the worker to permanent total disability payments at California's 2026 maximum rate of $1,764.11 per week (effective January 1, 2026, per the California DIR TTD/PTD rate announcement). Note: proposed legislation (AB 1329) that would have tightened SIBTF eligibility was vetoed by Governor Newsom in October 2025 — the current eligibility rules under §4751 remain in effect. Eligibility checklist:

• You have a documented permanent partial disability that existed before your most recent work injury
• Your new work injury caused at least 35% permanent disability on its own (unadjusted for age or occupation) — or at least 5% if it affects the opposite corresponding body part to your prior disability
• Your combined disability (prior + new) reaches 70% or more of total permanent disability
• You have not yet settled or resolved the SIBTF claim (it is separate from your employer's WC claim)
• You file your SIBTF application within a reasonable time after your permanent disability rating is determined by the WCAB