Values at the low end may be helpful, but noting the US median household income of $61,372, values at the upper end may
be less useful. Nonetheless, this table may be helpful in setting a
definition for the “low income” relevant to Z59.6.
The US Census Bureau defines “deep poverty” as living in a
household with a total cash income below 50 percent of its poverty threshold. Substituting “deep poverty” for “extreme poverty” and applying the “deep poverty” definition to the poverty
level table yields the following numbers for deep poverty/ex-treme poverty income:
< $6,070 for individuals
< $8,230 for a family of two
< $10,390 for a family of three
< $12,550 for a family of four
< $14,710 for a family of five
< $16,870 for a family of six
< $19,030 for a family of seven
< $21,190 for a family of eight
These values, the highest of which barely surpasses one-third of
median household income, seem to reflect dire economic circum-
stances. Having established some parameters for low income and
extreme poverty, the next challenge would be verifying the same.
Collecting tax return data would impose a number of burdens
upon providers and allied health staff before consideration of
what is arguably the financial equivalent of HIPAA—1999’s
Gramm-Leach-Bliley Act. At the provider level, collecting and
retaining objective data may be unworkable. If the provider is
part of a health system, some data may be available at the system level—for example, if the patient is in the system’s Health
Care Assistance Program. Absent the same, and given a likely
unwieldy circumstance of gathering and retaining income data
at the provider level, using subjective data provided by the patient may be necessary.
Subjective measures can gauge objective states. 7 Using subjective data to assess income is not inconsistent with techniques
used by the Census Bureau. In the absence of a system mechanism to capture and score objective financial data, providers
and practices should consider a set of subjective screening
questions to identify circumstances that reflect Z59.5 or Z59.6.
Consider permutations of questions for patients about their
level of difficulty in completing tasks related to their healthcare,
such as filling a prescription, taking into account the subjective
data elements used by the Census Bureau. 8 There should be
practice- or system-wide consensus in the assignment of codes
based upon this subjective questioning.
Determinant Two: Food Insecurity
The concept of “food security”—and its opposite “food insecuri-
ty”—dates back to the Life Sciences Research Office (LSRO) of the
Federation of American Societies for Experimental Biology report
based on the ad hoc panel convened in 1989 for the American In-
stitute of Nutrition, subsequently published in the Journal of Nutri-
tion. Studies appear to link food insecurity to a number of health
problems among the general population as well as increased as-
sistance with activities of daily living (ADLs) for seniors.
ICD-10-CM coding options include Z59.4, lack of adequate
food and safe drinking water.
Again, there are no Coding Clinic references for this code, but
organizations such as Hunger Vital Sign point to this code as appropriate for reporting food insecurity. 9
There are question sets that can be employed to gather subjective data, the result of which may trigger reporting Z59.4. The
USDA has a short questionnaire that has been found to be an effective measure of food security. The form is available at https://
The questionnaire includes a simple raw score template based
upon affirmative responses. Results fall into one of three categories: high or marginal food security, low food security, or very
low food security.
Reasonably, code Z59.4 is reportable with this measure of
low or very low food security. The USDA subjective questionnaire gives providers and staff a tool to assess food insecurity.
As previously mentioned, the code description does not explicitly mention food insecurity but Hunger Vital Sign does point to
this code for reporting food insecurity. There should be practice- and system-wide consensus to assigning code Z59.4 based
upon a standard questionnaire.
Determinant Three: Housing Instability
Studies have established a link between housing instability and
decreased health outcomes. According to the National Quality
Forum, “Individuals who are housing unstable have also been
found to be more likely to visit an emergency room, have longer
hospital stays … and have higher likelihoods of readmission.” 10
Housing instability is an important social determinant of health.
ICD-10-CM coding options include:
Z59.1, Inadequate housing
ICD-10-CM synonyms for Z59.1 include “lack of heating,” “re-
striction of space,” and “technical defects in home preventing
adequate care.” There are no Coding Clinic references for these
codes or their ICD-9-CM predecessors, V60.0 and V60.1. The
Centers for Disease Control and Prevention has set forth a defi-
nition for inadequate housing, available at https://www.cdc.
gov/mmwr/pdf/other/su6001.pdf. According to this definition,
“Inadequate housing is defined as an occupied housing unit
that has moderate or severe physical problems—deficiencies in
plumbing, heating, electricity, hallways, and upkeep.”
The American Housing Survey defines “severely inadequate”
based on an affirmative response to any of the following: 11
1. Unit does not have hot and cold running water.
2. Unit does not have a bathtub or shower.
3. Unit does not have a flush toilet.
4. Unit shares plumbing facilities.
5. Unit was cold for twenty-four hours or more, and more
than two breakdowns of the heating equipment have oc-