Medicare is adding to its do-not-pay list for hospitals two new categories of preventable conditions it won't cover. Last year, CMS determined it would no longer pay extra costs for treating certain preventable conditions, referred to as "never events." Medicare officials have now announced that it no longer will pay the extra-care costs associated with treating dangerous blood clots in the leg following knee or hip-replacement. The program also will not pay extra for complications stemming from poor control of blood sugar levels. The changes were made as part of a final rule setting payment rates for inpatient hospitals for the next fiscal year.