Analysis of Medicare claims data show wide regional variation in the amount and cost of medical care that Medicare beneficiaries receive. CSR is part of a Dartmouth-led research consortium conducting a 5-year study to better understand the causes and consequences of geographic variation in per capita expenditures for elderly patients. The Center is contributing to that effort by developing survey instruments for Medicare beneficiaries and physicians, conducting a national survey of physicians, and fielding a dual-mode (telephone to mail) survey of n=6,000 Medicare beneficiaries. The National Institute on Aging (NIA) is funding this work.