Contributory Share of Illness or Infirmity (Mitwirkungsanteil)

Concept

Accident insurance pays only for the consequences of an accident, not for illness or infirmity. Where the two coincide – for example where pre-existing arthrosis, osteoporosis or disc degeneration increases the extent of an injury or delays healing – the portion attributable to the non-accident cause is estimated as a contributory share in per cent. Under the German model conditions the percentage degree of disability is reduced by that share for the lump-sum disability benefit and the accident annuity, while for death and other benefits the benefit itself is reduced; no reduction is made below a contributory share of 25 per cent. Section 182 VVG confirms that where illness or infirmity has contributed, the benefit is reduced in proportion to that contribution.

Design in Germany, Austria and Switzerland

The Austrian model conditions (Art. 3 AUVB 2022) follow the same approach and leave the threshold as a contractual parameter; injuries co-caused by constitutional or degenerative factors are expressly included. Market practice shows a range of thresholds: German group and premium tariffs waive the reduction below a contributory share of 50 %, other group wordings and Austrian conditions reduce from 25 %; sports group contracts waive the degenerative-contribution defence altogether for injuries to limbs. Swiss mandatory accident insurance applies a different concept: under Art. 36 UVG, care benefits, cost reimbursements and daily allowances are not reduced where the injury is only partly a consequence of the accident, whereas disability pensions, integrity compensation and survivors’ pensions are reduced appropriately, disregarding any prior condition that had not previously reduced earning capacity. Swiss collective wordings, by contrast, provide for a proportionate benefit without any threshold, determined on the basis of a medical opinion.

Relevance for Claims and Underwriting

The contributory share is one of the most frequent points of dispute in settling disability benefits and regularly requires a medical opinion separating the accident-related from the degenerative component. It must be distinguished from the deduction for pre-existing disability (loss of function of the same body part existing before the accident) and from the exclusion of unrelated illnesses. The threshold is decisive for wording quality: the higher it is, the less often a reduction applies, which weighs particularly with older insured populations and group schemes with a mixed age structure.