Description: A simple short-term disability model is developed, where the loss process is comprised of two processes: new claims process and continuing claims process. This results in a surplus function with stationary dependent increments. Three dimensional transitional probabilities are needed to model the transitions of this non-Markovian process. An approximating model with stationary independent increments is found. The approximating model leads to bounds for the finite probability of ruin. Numerical comparisons are made.