The risk of coal workers' pneumoconiosis (CWP) and other lung disorders among US coal miners was examined. Data on the incidence of simple CWP, progressive mass fibrosis (PMF) and clinically significant deficits in lung function taken from two rounds of the National Study of CWP and exposure data from coal mine dust sampling programs were analyzed. The models were used to predict the prevalence and excess risk of simple CWP, PMF, and 1 second forced expiratory volume (FEV1) deficits as a function of age, cumulative exposure to coal mine dust, rank of coal mined, and smoking status. Point risk estimates for developing category 1 CWP at age 65 year (yr) for mining high rank bituminous coal over a 45yr working lifetime at coal dust exposures of 0.5, 1.0, or 2.0mg/m3 varied from 41 to 48, 108 to 119, and 338 to 348 cases per 1,000, respectively. Point risk estimates for PMF for the same exposures and coal rank were 13, 34 to 36, and 114 to 15, respectively. The risk estimates were similar for exposure to dusts associated with other ranks of coal. For exposure durations shorter than 45yr, the point estimates of the PMF risk at age 65 at a coal dust exposure of 2.0mg/m3 varied from 1 to 155 cases/1,000. Point estimates for developing deficits in FEVC1 at age 65yr varied from 9 to 188 cases/1,000 for all miners exposed to 0.5, 1.0, and 2.0mg/m3 coal dust over a 45yr working lifetime. Among miners who never smoked, the point estimate for developing FEV1 deficits at age 65 for 45yr exposure to 2.0mg/m3 coal dust varied from 9 to 12 cases/1,000. For smoking miners, the corresponding point estimates were 15 to 19 cases/1,000. The authors conclude that US coal miners have a significantly increased risk of developing occupational lung diseases from being exposed to coal mine dust at 2.0mg/m3 over a working lifetime. To reduce this risk, NIOSH recommends that the current coal mine dust standard be lowered to 1.0mg/m3.