Military Health Care provides medical care on military bases to current armed forces members and their dependents. Medical care from the VA is available to honorably discharged veterans who either have a service connected illness, injury, or disability, or whose incomes are near or below poverty. The Field Representative's Manual for 1997-2003 provided the following definition for this first set of military health care programs: "Military health care/VA refers to health care available to active duty personnel and their dependents; in addition, the VA provides medical assistance to veterans of the Armed Forces, particularly those with service-connected ailments."

The Civilian Health and Medical Program Uniform Service of the Department of Defense (CHAMPUS) is a health care benefits program that provides in-patient and out-patient care from civilian sources and Military Treatment Facilities, on a cost sharing basis. In the late 1990s, a managed care approach was phased in, under the name TRICARE. Retired members of the military are eligible for such coverage, as are the dependents of active-duty, retired, and deceased military.

The Civilian Health and Medical Program of the Department of Veterans Affairs (CHAMPVA) is a health benefits program in which the Department of Veterans Affairs shares the cost of health care services and supplies with eligible beneficiaries. Persons eligible for TRICARE/CHAMPUS are not eligible for CHAMPVA coverage. Persons potentially eligible for CHAMPVA coverage are: the spouse or child of a veteran who has been rated permanently and totally disabled for a service-connected disability by the VA; the surviving spouse or child of a veteran who died from a VA-rated service connected disability; the surviving spouse or child of a veteran who was at the time of death rated permanently and totally disabled; or the surviving spouse or child of a military member who died in the line of duty.

The Field Representative's Manual provided two definitions for this second set of military health care programs. For 1997-2000, the Manual stated, "CHAMPUS (Comprehensive Health and Medical Plan for the Uniformed Services) provides health care in private facilities for dependents of military personnel on active duty or retired for reasons other than disability. TRICARE is the 'managed care' version of CHAMPUS. CHAMP-VA (Comprehensive Health and Medical Plan of the Veterans Administration) provides health care for the spouse, dependents, or survivors of a veteran who has a total, permanent service-connected disability." The definition in the Manual for 2001 was more extensive:

The categories listed were:

• Private health insurance (2004 forward)

• Private health insurance plan from employer or workplace (1997-2003)

• Private health insurance plan purchased directly (1997-2003)

• Private health insurance plan through a State or local government program or community program (1998-2003)

• Medicare (1997 forward)

• Medi-Gap (1997 forward)

• Medicaid (1997 forward)

• CHIP (Children's Health Insurance Program) (1999 forward)

• Military Health Care/VA (1997-2003)

• Military Health Care (CHAMPUS/TRICARE/CHAMP-VA) (1997-2018)

• Military related health care: TRICARE (CHAMPUS)/VA health care/CHAMP-VA (2019 forward)

• Indian Health Service (1997 forward)

• State-sponsored health plan (1997 forward)

• Other government program (1997 forward)

• Single Service Plan (e.g., dental, vision, prescriptions) (1999-2018)

• No coverage of any type (2000 forward)

Respondents were consistently instructed to exclude private plans that "only provide extra cash while hospitalized." In 1997-1998 respondents were also instructed to "EXCLUDE private plans that ... pay for only one type of service (nursing home care, accidents, or dental care)." Between 1999 and 2018, "Single Service Plan" was added as a possible response, and, consequently, the instructions were changed to read, "INCLUDE those [private plans] that pay for only one type of service (nursing home care, accidents, or dental care)." Beginning in 2019, respondents were asked three separate questions to determine if they had single service plans for dental services, vision services, and/or prescriptions.

In follow-up questions, interviewers recorded the names of up to four private health insurance plans. If the person was reported as covered by CHIP (beginning in 2000), by a state-sponsored health plan, or by another public program (other than Medicaid) that paid for health care, the interviewer recorded the name of that plan. The placement and wording of these questions about the names of specific government health care plans varied across years.

For persons initially reported as not having health care coverage of any kind, interviewers asked whether the person had Medicare coverage, Medicaid coverage, coverage via a Medicaid program or non-Medicaid state-sponsored health insurance program with the appropriate name for the state, CHAMPUS or CHAMPVA coverage, or any private insurance. For those who acknowledged any such coverage, the interviewer repeated the series of questions mentioned above to determine the specific type of coverage.

In addition to HIMILITE, IPUMS NHIS contains the following recoded insurance variables: HIHSE (Covered by Indian Health Service: Recode); HIPRIVATEE (Covered by private health insurance: Recode); HICHIPE (Covered by Children's Health Insurance Program: Recode); HIMCAIDE (Covered by Medicaid: Recode); HIMCAREE (Covered by Medicare: Recode); HISTATEE (Covered by other state-sponsored health plan: Recode); HIOTHGOVE (Covered by other government program: Recode); and HINOTCOVE (No coverage of any type: Recode).