Dialysis patients require numerous medications and have high prescription drug costs compared with general Medicare patients, possibly making them more vulnerable to Medicare Part D policy-related issues. The purpose of this study was to identify problems that dialysis patients experience with Medicare Part D through a survey of dialysis social workers. The online survey was posted on www.kidneyhealthcarecoverage.org and results were collected from January 2010 through October 2010. It was completed by 184 social workers in 38 states, representing 14,200 patients. The greatest Part D plan restrictions were seen with the highest cost prescription medications--Lanthanum carbonate, sevelamer carbonate, and cinacalcet. Seventeen percent of social workers reported that dialysis patients were "very frequently" or "frequently" unaware of available Medicare Part D coverage and 54% reported that up to 20% of their patients continued to have no insurance coverage for prescription drugs. Social workers reported that patients affected by the coverage gap exhibited various changes in medication-taking behavior, such as skipping doses and decreasing dosing frequency. Higher out-of-pocket costs for some dialysis patients during the coverage gap led to reduced use of medications; such gaps in treatment could lead to increased use of medical services, but further data are needed. Currently, the government is slowly phasing out the coverage gap; this process should be completed by 2020. The anticipated shift of self-administered bone and mineral disorder medications from Part D into the dialysis bundle in 2014 has the potential to affect dialysis patients' access to these medications.