The Combined Values Chart, Explained

Add up the impairments on a multi-part case and you’ll overshoot the real rating every time. California combines them instead, using the PDRS’s Combined Values Chart (CVC) — the last step before a rating becomes weeks and dollars. Here’s the logic, the formula, and the places it changes outcomes.

The idea: percentages of what’s left

A PD rating is a percentage of the whole person. If a spine injury takes 20%, the next impairment can only impair the 80% that remains. So a second 20% impairment takes 20% of the remainder — 16 points — and the total lands at 36, not 40. Stack as many impairments as you like; the total approaches but never reaches 100%.

Reference combinations

A few anchors worth knowing cold (every value below is computed by the same engine that runs the calculator; every pair from 1 to 99 is in the printable Combined Values Chart PDF):

Three or more impairments

With several body parts, the finals are folded pairwise, largest first — combine the two biggest, combine the result with the next, and so on, rounding at every step. The sample case’s 18% shoulder, 11% spine, and 7% neck fold as 18 C 11 = 27, then 27 C 7 = 32% PD. Because of the per-step rounding, a different order can occasionally land a point off — largest-first is the canonical PDRS order. The chart itself is a rebuttable default: under the Appeals Board’s en banc Vigil v. County of Kern (2024), impairments may be added instead when the medical evidence shows how each affects activities of daily living and that those effects don’t overlap or overlap in a way that amplifies them (see Almaraz/Guzman and Kite).

The same-limb wrinkle

Two impairments to the same arm combine with each other before they meet the rest of the body. Each is rated and apportioned on its own, the arm’s ratings combine on the chart, and that composite is capped at the value of amputating the arm — a limb can never rate worse than its loss. (Two findings in one part, like a shoulder’s instability and its lost motion, combine even earlier, on the arm’s own scale, before conversion to whole-person terms.) Multi-region cases therefore combine at two levels: within the extremity, then across the body.

Why one point at the top matters so much

The CVC decides which side of a statutory threshold a case lands on, and the thresholds are cliffs, not slopes:

The same cliff logic applies at 100% (permanent total disability, lifetime indemnity at the TD rate). When a case sits near a threshold, test the disputed impairment both ways in the calculator — the scenario compare shows what each contested point is actually worth.