The objective of this study was to evaluate the association between days lost due to specific diseases and total days lost due to disease in 2 consecutive lactations using a new measure called the disease-adjusted lactation (DALact). The DALact is a health measure that incorporates morbidity and removal (death or culling) into a single time-based summary measure and it represents a new approach for assessing the impact of diseases in a lactation. Health and removal data were obtained from a Colorado dairy with approximately 1,400 lactating cows. Multiparous cows (n = 805) that calved, were sold, or died from July 1, 2015, through June 30, 2016, were selected. Individual cow health data were collected from Dairy Comp 305 for the recently completed lactation and from the previous lactation. Health events included calving injury, displaced abomasum, diarrhea, hypocalcemia, ketosis, lameness, mastitis, metritis, musculoskeletal injuries, pneumonia, and retained placenta. All cow-level data were imported into SAS for validation, calculation of DALact, and analysis. The DALact was calculated adding the Days Lost due to Premature Death or Culling (DLRD) and the Days Lost due to Illness (DLI). DLRD was calculated as the difference between the average completed lactation days in milk for the herd and the days in milk at culling or death for individual cows. The DLI was the product of the number of cases of each disease multiplied by established disability weights and estimated disease durations (days) for a specific disease. The association between DALacts in 2 consecutive lactations was evaluated using PROC GLM. P-values < 0.05 were considered significant. Positive significant associations (P < 0.001) were found between DALacts in 2 consecutive lactations for lameness and mastitis. Similarly, the total DALacts in 2 consecutive lactations were also significantly associated (P < 0.001). Identification of diseases and reasons for removal that significantly affect time lost during 2 consecutive lactations will help producers focus management and preventive measures on diseases having the greatest impact on future productivity and wellbeing.