There is not a universally agreed-upon definition of which sources of health insurance and health care are "private" and which sources are "public or government." Therefore, beginning with the 2001 Panel the answer categories for the recode variable RPRVHI have been expanded to include the values of "-1" Not in Universe, "3" Military related, and "4" Others. Additionally, recode variable RPRVHI2 has been added to identify the 2nd type of health insurance coverage respondents may have. The additional answer categories, as well as variable RPRVHI2, give data users the flexibility to include or exclude "Military related" health insurance as a type of private health insurance. Ultimately, the new categories allow users to define non-Medicaid and non-Medicare health insurance (such as employer-provided insurance) and health care sources (such as military/VA health care) as government or private according to their own definition and research needs.

Throughout the 2001 Panel, variable EHIMTH(PX) indicates respondents with health insurance coverage other than Medicare or Medicaid. EHIMTH ask "Was ... covered by a health insurance plan other than Medicare or Medicaid?" Valid response categories are either (1) "Yes" or (2) "No."

In the 2001 Panel, there are instances in each wave where respondents are assigned a value of -1 "Not in Universe." This happened because there were no health insurance coverage units (EHIUNT) listed which allowed these respondents to be linked to a coverage unit.

In the above cases, when no health insurance units linked respondents to an insurance policy EHIMTH(PX) was assigned a value of -1 "Not in universe." These -1 values appear on the public use data file. However, -1 "Not in universe" is not listed as a valid value for technical documentation purposes, as either a person is, or is not, covered by health insurance (other than Medicare or Medicaid).

For the 2001 Panel, EHIMTH(PX) values of -1 "Not in universe" may safely be interpreted as no coverage, the same as the value of (2) "No."

For the 2004 Panel and beyond, any -1 "Not in universe" responses will be converted in the edit process to a value of (2) "No."