24 pages. Excerpt: We find that the measures of out-of-pocket spending in the [Health and Retirement Study (HRS)] are about 50% greater than those in [the Medical Expenditure Panel Survey (MEPS)] at the mean, and very much greater at the upper points of the distribution. HRS and MCBS are in better agreement, although the HRS is higher at the mean and at the top of the distribution. The implication is that the level and risk of out-of-pocket spending on health care are exaggerated in HRS. Observation error in the HRS measurement relative to MEPS and MCBS is to be expected,but this does not explain the apparent bias. We conclude that researchers who use HRS 2004 or earlier should examine health care spending carefully, even on a case-by-case basis.