The$Urban$Institute$Health$Policy$Center’s$$
Medicaid/CHIP$Eligibility$Simulation$Model$
$
March$2014$
!
This!document!describes!the!Urban$Institute$Health$Policy$Center’s$Medicaid/CHIP$
Eligibility$Simulation$Model$based$on$the$American$Community$Survey$(ACS)$and$the$
Puerto$Rico$Community$Survey$(PRCS).$The!model!is!a!microsimulation!that!uses!local2
area!rules!about!Medicaid/CHIP!eligibility!to!approximate!adults’!and!children’s!
eligibility!for!Medicaid!and!CHIP.!!The!model!was!first!developed!under!a!grant!from!the!
Robert!Wood!Johnson!Foundation!(RWJF)!and!builds!on!a!model!developed!for!the!
Current!Population!Survey!Annual!Social!and!Economic!Supplement!(CPS2ASEC)!by!Lisa!
Dubay!and!Allison!Cook.!!It!has!been!used!to!simulate!eligibility!in!the!50!states!and!
Washington!DC!for!the!years!200822012!(before!the!Affordable!Care!Act![ACA]!was!
implemented)!and!2014!(simulating!the!new!coverage!provisions!of!the!ACA).!It!has!also!
been!used!to!simulate!eligibility!in!Puerto!Rico!in!2011!and!enrollment!under!
hypothetical!statehood.!!Results!from!the!model!have!been!used!in!a!variety!of!reports!
and!publications!(e.g.,!Kenney!et!al.!2010,!2011,!2012).!Below!we!describe!the!ACS!and!
PRCS,!explain!the!data!edits!we!apply,!and!discuss!how!we!identify!eligibility!for!both!
children!and!adults.!!!
!
American)Community)Survey)(ACS))
!
The!ACS!is!an!annual!survey!fielded!by!the!U.S.!Census!Bureau.!We!use!an!augmented!
version!of!the!ACS!prepared!by!the!University!of!Minnesota!Population!Center.!Known!
as!the!Integrated!Public!Use!Microdata!Sample!(IPUMS),!it!employs!the!public!use!
sample!of!the!ACS!and!contains!edits!for!family!relationships!and!other!variables!
(Ruggles!et!al.!2010).!The!2009!ACS!has!a!reported!household!response!rate!of!98.0!
percent,!ranging!from!94.9!percent!in!the!District!of!Columbia!to!99.4!percent!in!Indiana!
and!Wisconsin!(U.S.!Census!Bureau!2012).!The!survey!uses!an!area!frame!that!includes!
households!with!and!without!telephones!(land!line!or!cellular).!It!is!a!mixed2mode!
survey!that!starts!with!a!mail2back!questionnaire—52.7!percent!of!the!civilian!
noninstitutionalized!sample!was!completed!by!mail!in!2009!(Mach!and!O’Hara!2011)—
and!is!followed!by!telephone!interviews!for!initial!nonresponders;!it!is!further!followed!
by!in2person!interviews!for!a!subsample!of!remaining!nonresponders!(Griffin!and!
Hughes!2010).!We!restrict!our!estimates!to!the!civilian!noninstitutionalized!population.!
!
In!2008,!a!question!was!added!to!the!ACS!to!ask!respondents!about!coverage!of!each!
individual!in!their!households!by!any!of!the!following!types!of!health!insurance!or!health!
plans!at!the!time!of!the!survey:!
!
a. Insurance!through!a!current!or!former!employer!or!union!(of!this!person!or!
another!family!member);!!
!
1!
b. Insurance!purchased!directly!from!an!insurance!company!(by!this!person!or!
another!family!member);!!
c. Medicare,!for!people!65!and!older,!or!people!with!certain!disabilities;!!
d. Medicaid,!Medical!Assistance,!or!any!kind!of!government2assistance!plan!for!
those!with!low!incomes!or!a!disability;!!
e. TRICARE!or!other!military!health!care;!!
f. VA![Department!of!Veterans!Affairs]!(including!those!who!have!ever!used!or!
!enrolled!for!VA!health!care);!!
g. Indian!Health!Service;!!
h. Any!other!type!of!health!insurance!or!!health!coverage!plan!(respondents!are!
asked!to!specify).!!!
!
Multiple!types!of!coverage!can!be!identified!for!each!person,!and!people!identified!as!
not!having!coverage!under!categories!a!through!f!(or!recoded!to!another!category!from!
the!write2in!option,!category!h)!are!considered!uninsured!(Turner!and!Boudreaux!2010).i!
Since!the!data!are!collected!continuously!over!a!122month!period,!the!coverage!
estimates!represent!an!average!day!in!the!calendar!year.!
!
With!the!exception!of!private!nongroup!coverage!and,!to!a!lesser!extent,!Medicaid,!
research!suggests!that!the!ACS!coverage!estimates!released!by!the!Census!Bureau!are!
generally!valid!for!policy!purposes!(Boudreaux!et!al.!2011),!with!estimates!for!the!other!
coverage!categories!fairly!similar!to!those!from!the!CPS2ASEC!and!the!National!Health!
Interview!Survey!(NHIS)!(Turner!and!Boudreaux!2010),!which!are!commonly!used!to!
study!insurance!coverage.!
!
In!an!effort!to!correct!for!the!apparent!misclassification!of!private!nongroup!coverage!
and!Medicaid/CHIP!in!the!ACS,!and!to!define!coverage!as!including!only!comprehensive!
health!insurance!as!opposed!to!single2service!plans!(e.g.,!dental!coverage),!we!
developed!a!set!of!logical!coverage!edits!that!are!applied!if!other!information!collected!
in!the!ACS!implies!that!coverage!for!a!sample!case!likely!has!been!misclassified!(Lynch!et!
al.!2011;!Lynch!and!Kenney!2011).!We!draw!from!approaches!that!have!been!applied!to!
other!surveys!(National!Center!for!Health!Statistics!2005)!and!build!on!ACS!edit!rules!
used!by!the!Census!Bureau!(Lynch,!Boudreaux,!and!Davern!2010).!Preliminary!analysis!
aimed!at!assessing!the!validity!of!these!edits!suggests!that!they!move!the!ACS!coverage!
estimates!closer!to!administrative!totals!for!Medicaid!(Lynch!and!Resnick!2013).!
!
For!example,!we!edit!sample!adults!reporting!private!nongroup!coverage!to!Medicaid!if!
they!are!simulated!as!eligible!for!Medicaid,!a!parent!of!a!dependent!child,!and!enrolled!
in!the!Supplemental!Nutrition!Assistance!Program!(SNAP)/food!stamps!or!public!
assistance,!assuming!that!the!reported!private!nongroup!coverage!is!an!error!(perhaps!
the!report!of!a!premium!payment)!because!families!with!incomes!low!enough!to!qualify!
for!other!public!benefits!likely!cannot!afford!to!purchase!nongroup!health!insurance!
coverage!on!the!individual!market.!We!also!edit!sample!adults!reporting!both!Medicaid!
and!employer2sponsored!insurance!(ESI)!to!ESI!only!if!they!are!not!simulated!as!
!
2!
Medicaid2eligible!(assuming!that!the!reported!Medicaid!coverage!is!a!survey2processing!
error!or!that!it!is!for!wrap2around!coverage!or!for!narrowly!defined!services,!such!as!for!
family!planning).!In!2009,!the!additional!edits!increased!the!estimated!number!of!
uninsured!adults!from!the!ACS!by!1!million!and!decreased!the!number!of!adults!with!
Medicaid!coverage!by!58,000.!After!editing,!our!derived!estimate!of!the!number!of!
uninsured!adults!is!39.4!million,!relative!to!the!NHIS!uninsured!estimate!of!39.2!million!
for!2009,!and!our!derived!estimate!of!the!number!of!adults!with!Medicaid!is!16.8!
million,!compared!with!17.1!million!from!the!NHIS!(authors’!tabulations).ii!!The!impact!
of!the!edits!is!similar!in!other!data!years.!
!
For!children,!the!ACS!edits!address!inconsistent!coverage!reporting!based!on!what!we!
know!about!Medicaid/CHIP!eligibility!rules!and!what!we!know!about!the!children’s!
families!from!the!survey!(e.g.,!that!it!is!unlikely!that!a!non2disabled!parent!would!be!
enrolled!but!that!their!eligible!child!would!not),!reclassifying!children!with!illogical!
combinations!of!coverage!and!family!data!to!Medicaid/CHIP!where!appropriate.!For!
instance,!in!2008,!the!edits!reduced!the!estimated!number!of!uninsured!children!in!the!
survey!from!8.2!million!to!7.3!million,!which!is!slightly!lower!than!the!NHIS!estimate!of!
7.4!million!uninsured!children!for!the!same!period.iii!Our!edits!increased!the!estimated!
number!of!children!with!Medicaid/CHIP!as!their!primary!coverage!by!roughly!4.4!million!
to!a!level!that!is!just!about!7!percent!lower!than!the!comparable!administrative!count!
for!June!2008.iv!
!
Puerto)Rico)Community)Survey)
)
The!Puerto!Rico!Community!Survey!(PRCS)!is!the!Puerto!Rico!implementation!of!the!ACS!
that!is!conducted!in!the!50!states!and!the!District!of!Columbia.!The!design!is!very!similar!
to!the!ACS,!and!we!use!an!augmented!version!of!the!public2use!PRCS!prepared!by!the!
University!of!Minnesota!Population!Center!because!it!contains!edits!for!family!
relationships!and!other!variables!(Ruggles!et!al.!2010).!
!
We!edited!a!small!number!of!cases!with!illogical!coverage!based!on!an!analysis!in!which!
we!compared!the!direct!Medicaid!and!Medicare!estimates!to!administrative!counts!of!
Medicare!and!Medicaid!and!also!evaluated!them!for!internal!consistency!(primarily!
within!families!with!respect!to!income!and!Medicaid/CHIP!eligibility).!We!also!edited!the!
coverage!of!people!in!families!with!government!employees!because!they!receive!
coverage!through!the!Medicaid!system!but!it!is!not!Medicaid.!
!
Eligibility)Simulation))
)
The!Urban!Institute!Health!Policy!Center!Medicaid/CHIP!Eligibility!Simulation!Model!for!
the!ACS!and!PRCS!simulates!eligibility!for!Medicaid/CHIP!using!available!information!on!
eligibility!guidelines,!including!income!thresholds!for!the!appropriate!familyv!size,!asset!
tests,!parent/family!status!(for!adults),!and!the!amount!and!extent!of!income!
!
3!
disregards,!for!each!program!and!state!in!place!as!of!the!middle!of!that!data!year!
(Cohen!Ross!et!al.!2008;!Cohen!Ross!et!al.!2009;!Heberlein!et!al.!2011,!2012;!Kaiser!
Commission!on!Medicaid!and!the!Uninsured!2010,!2011a).vi!For!noncitizens,!as!in!some!
prior!studies,!the!model!also!takes!into!account!length!of!residency!in!the!United!States!
in!states!where!this!is!a!factor!in!eligibility!(National!Immigration!Law!Center!2011;!
Sullivan!2010).!Because!the!ACS!does!not!contain!sufficient!information!to!determine!
whether!an!individual!is!an!authorized!immigrant!and!therefore!potentially!eligible!for!
Medicaid!coverage,!we!impute!documentation!status!for!noncitizens!in!the!50!states!
and!the!District!of!Columbia!based!on!a!model!used!in!the!CPS2ASEC!(Resnick!2013).!
Documentation!status!is!imputed!to!immigrant!adults!in!two!stages!using!individual!and!
family!characteristics,!based!on!an!imputation!methodology!that!was!originally!
developed!by!Passel!(Passel!and!Cohen!2009).!The!approach!is!designed!to!produce!
imputations!that!match,!in!the!aggregate,!published!summary!estimates!of!the!U.S.!
undocumented!population,!nationally!and!in!a!subset!of!large!states!(California,!New!
York,!New!Jersey,!Florida,!Illinois,!and!Texas).!
!
Pre9ACA)Nonelderly)Adult)Eligibility)in)the)50)States)and)the)District)of)Columbia)
!
For!adults!(those!ages!19!to!64),!our!ACS!model!identifies!eligibility!for!comprehensive!
Medicaid!or!Medicaid2equivalent!benefits!using!state!rules!for!major!pathways!for!
adults.!The!following!pre2ACA!eligibility!pathways!are!modeled!(they!correspond!roughly!
to!the!order!in!which!caseworkers!or!state!eligibility2determination!software!typically!
check!for!eligibility):vii!
!
1. Aged2out!foster!children!(young!adults!who!were!foster!children!who!qualify!
for!Medicaid);!!
2. Supplemental!Security!Income!(SSI)!(adults!who!receive!SSI!income!are!
deemed!Medicaid2eligible!because!they!are!enrolled!automatically!in!most!
states);!!
3. Section!1931!(usually!parents!of!minors!whose!incomes!fall!below!the!
Temporary!Assistance!for!Needy!Families![TANF]!income!cut2offs);!!
4. Aged/Blind/Disabled!(adults!with!functional!limitations!who!meet!the!
qualifications!for!aged/blind/disabled!coverage);!!
5. Section!1115!Waivers!(adults!who!meet!the!qualifications!for!eligibility!in!
states!with!Section!1115!programs!that!provide!comprehensive!Medicaid!or!
Medicaid2equivalent!benefits);!!
6. Medically!Needy!(adults!categorically!eligible!for!medically!needy!coverage!
who!meet!the!income!qualifications!for!eligibility);!
7. Relative!caretakers!(adults!who!are!not!parents!of!minors!but!appear!to!be!
relative!caretakers!of!Medicaid2enrolled!minors!not!living!with!their!parents).!
!
In!addition,!the!modeling!can!include!exploratory!analysis!of!eligibility!and!participation!
where!we!include!adults!who!are!ineligible!for!comprehensive!Medicaid!in!the!
simulation!but!either:!1)!are!eligible!for!federally!funded!Section!1115!Medicaid!
!
4!
coverage!(such!as!Commonwealth!Care!in!Massachusetts)!or!state2funded!coverage!
(such!as!the!Basic!Health!Plan!in!Washington)!that!is!more!limited!in!scope!than!
comprehensive!Medicaid!(Heberlein!et!al.!2011)!(we!refer!to!these!adults!as!‘‘limited!
benefit!eligibles’’viii),!or!2)!fall!into!particular!Medicaid!categorically!eligible!groups!but!
do!not!meet!all!the!requirements!for!eligibility!according!to!the!information!available!on!
the!ACS!and!the!rules!we!have!(known!as!‘‘imputed!eligibles’’).!In!2009,!of!the!7.4!
million!adults!with!Medicaid!coverage!who!do!not!appear!eligible!for!comprehensive!
Medicaid!services!through!the!main!pathways!that!are!simulated,!1.4!million!are!eligible!
for!limited!coverage!(0.7!million!for!limited!Medicaid!coverage!and!0.7!million!for!state2
funded!coverage),!and!3.6!million!meet!the!categorical!requirements!for!eligibility!for!
comprehensive!Medicaid!coverage!but!have!reported!income!levels!slightly!above!the!
eligibility!thresholds!that!are!modeled!(i.e.,!these!are!so2called!imputed!eligibles,!many!
of!whom!are!likely!eligible!for!pregnancy2related!services!but!are!not!modeled!in!the!
core!eligibility!model!because!we!do!not!have!information!on!pregnancy!status).ix!Our!
core!estimates!do!not!include!these!groups.!
!
Pre9ACA)Child)Eligibility)in)the)50)States)and)the)District)of)Columbia)
!
Children!are!defined!as!those!18!and!younger!in!the!civilian!noninstitutionalized!
population,!including!college!students!in!dorms!and!a!small!number!of!other!children!
living!in!group!quarters,!such!as!residential!treatment!facilities.!Children’s!individual!and!
family!characteristics,!including!income!and!citizenship!status,!are!compared!to!the!rules!
for!Medicaid!and!CHIP!in!their!state!of!residence.!The!following!eligibility!pathways!are!
modeled:!
!
1. Title!IV2E!(foster!children)!
2. SSI2related!
3. AFDC2related/Section!1931!(usually!children!whose!family!incomes!fall!below!
the!Temporary!Assistance!for!Needy!Families![TANF]!income!cut2offs)!
4. Poverty2related!(by!age!group!for!children!above!the!AFDC!thresholds)!
5. CHIP!(both!Medicaid!expansion!CHIP!and!separate!CHIP!programs)!
!
We!define!participation!rates!as!the!ratio!of!eligible!children!enrolled!in!Medicaid/CHIP!
to!those!children!plus!uninsured!children!who!are!eligible!for!Medicaid/CHIP.!In!our!core!
estimates,!we!excluded!from!these!counts!children!enrolled!in!one!of!the!programs!who!
also!have!other!coverage!(such!as!private!or!military!coverage)!and!those!with!
Medicaid/CHIP!coverage!who!do!not!have!a!known!eligibility!pathway.x!We!do!not!
currently!have!a!method!for!including!in!the!denominator!of!the!participation!rate!those!
uninsured!children!who!may!similarly!be!eligible!for!Medicaid/CHIP!coverage!but!do!not!
appear!to!be!based!on!the!information!that!is!available!on!the!survey.!
!
Post9ACA)Child)Eligibility)in)the)50)States)and)the)District)of)Columbia)
)
!
5!
A!number!of!changes!under!the!ACA!could!affect!some!children’s!Medicaid/CHIP!
eligibility,!including:!(1)!children!below!133!percent!of!FPL!in!separate!CHIP!programs!
are!moving!to!the!Medicaid!delivery!system!and!benefits!package!as!a!new!national!
Medicaid!floor!of!133!percent!of!FPL!is!established;!(2)!the!determination!of!how!much!
income!families!have!in!comparison!to!the!thresholds!is!changing!from!being!based!on!
states’!income!counting!rules!to!being!based!on!Modified!Adjusted!Gross!Income!
(MAGI),!and!certain!types!of!income!will!be!treated!differently!(Department!of!Health!
and!Human!Services!2013,!Centers!for!Medicare!and!Medicaid!Services!2012,!
Department!of!Health!and!Human!Services!2012,!Kaiser!Commission!on!Medicaid!and!
the!Uninsured!2012);xi!(3)!instead!of!using!income!disregards!that!vary!across!states!and!
across!families’!circumstances,!Medicaid/CHIP!eligibility!is!now!calculated!using!a!flat!5!
percent!disregard;!(4)!states!have!converted!their!pre2ACA!Medicaid/CHIP!eligibility!
thresholds!to!MAGI2based!thresholds!such!that!the!new!thresholds!are!not!less!than!the!
effective!income!levels!that!were!in!place!at!the!time!of!enactment!of!the!ACA!(which!
will!be!used!not!only!to!determine!who!is!eligible!for!Medicaid!or!CHIP,!but!also!to!
determine!the!federal!match!for!each!enrollee);!and!(5)!definitions!of!families!and!
whose!income!is!included!when!comparing!to!Medicaid/CHIP!thresholds!is!changing!
from!states’!definitions!of!families!to!the!tax!filing!unit!(Kaiser!Commission!on!Medicaid!
and!the!Uninsured!2011b).!As!of!January!2014,!reflecting!many!of!these!changes,!the!
median!upper!income!limit!for!Medicaid/CHIP!for!children!is!255!percent!of!the!FPL,!
with!almost!all!children!below!138!percent!of!FPL!eligible!for!Medicaid!(Heberlein!et!al.!
2013).!To!estimate!projected!Medicaid/CHIP!eligibility!for!children!under!ACA!
implementation,!we!added!modules!to!our!model!of!current!eligibility!to!address!the!
relevant!policy!changes!(Lynch!et!al.!2013).!Our!ACA!simulation!reflects!the!current!
Centers!for!Medicare!and!Medicaid!Services!(CMS)!guidance!at!the!time!it!was!
constructed!regarding!how!eligibility!would!be!determined!under!the!ACA.!We!also!
added!modules!for!testing!different!assumptions!about!how!the!law!would!be!
implemented.!!
!
Eligibility)and)Enrollment)in)Puerto)Rico)
)
We!apply!the!model!to!the!PRCS!data!in!much!the!same!way!as!we!do!to!the!ACS!data.!
The!model!simulates!eligibility!for!Medicaid!and!CHIP!by!mimicking!how!eligibility!is!
determined!by!a!caseworker!or!with!intake!software,!to!the!extent!possible!based!on!
variables!included!in!the!PRCS!and!the!Puerto!Rico!eligibility!rules!that!we!were!able!to!
collect.!We!collected!detailed!eligibility!rules,!including!the!income!thresholds!for!family!
units!of!different!sizes!and!according!to!parental!status,!asset!tests,!and!the!amount!and!
extent!of!income!disregards!(employment!expenses,!childcare!expenses,!etc.)!for!the!
different!eligibility!pathways!available!as!of!approximately!June!of!2011.!!For!each!
person,!the!model!identifies!and!takes!into!account!the!members!of!the!family!whose!
income!and!other!characteristics!the!Puerto!Rico!Medicaid!system!uses!in!determining!
eligibility.!!
!
!
6!
There!are!a!number!of!important!ways!in!which!the!simulation!for!Puerto!Rico!differs!for!
from!the!50!states!and!the!District!of!Columbia.!We!do!not!impute!undocumented!
status!because!we!know!of!no!available!data!on!Puerto!Rico!to!use!in!the!model!of!
undocumented!status.!For!computing!each!person’s!family!income2to2poverty!ratio!at!
baseline!we!use!Puerto!Rico’s!Commonwealth!Poverty!Level!(CPL)!methodology!instead!
of!the!methodology!from!the!Department!of!Health!and!Human!Services!(HHS)!used!for!
the!50!states!and!the!District!of!Columbia.!The!eligibility!pathways!for!Puerto!Rico!also!
differ!from!those!used!in!the!ACS!simulation,!and!we!check!for!eligibility!for!the!elderly!
as!well!as!the!nonelderly.!At!baseline,!the!following!eligibility!pathways!are!modeled:!
!
1. The!Puerto!Rican!Federal!Medicaid!program!(for!children,!parents!of!dependent!
children,!the!disabled,!and!the!elderly!with!family!income!less!than!100!percent!
of!CPL)!
2. The!Children’s!Health!Insurance!Program!(for!children!with!family!income!
between!100!and!200!percent!of!CPL)!
3. State!Medicaid!Program!(other!children!and!adults!and!disabled!and!elderly!with!!
family!income!between!100!and!200!percent!of!CPL)!
We!also!simulate!eligibility!under!hypothetical!statehood.!For!modeling!statehood!we!
applied!the!federal!minimum!requirement!for!eligibility!in!the!states!as!a!hypothetical!
minimum!although!all!states!have!substantially!more!expansive!eligibility!rules.!We!also!
applied!a!set!of!rules!that!met!the!federal!requirements!for!states!and!carried!over!as!
many!of!Puerto!Rico’s!current!rules!as!possible.!Under!this!scenario,!the!following!
eligibility!pathways!are!modeled:!
!
1. Title!IV2E!(foster!children)!
2. SSI!related!
3. AFDC/1931!(children,!parents,!and!relative!caretakers)!
4. Poverty2related!(children)!
5. CHIP!
We!also!project!enrollment!under!the!alternative!statehood!scenarios.!Consistent!with!
simulation!models!that!have!been!applied!to!the!rest!of!the!country,!we!assumed!100!
percent!take2up!for!current!Medicaid/CHIP!enrollees!(including!those!not!simulated!as!
eligible),!SSI!enrollees,!and!TANF!enrollees.!For!all!other!eligible!people,!we!apply!take2
up!rates!observed!for!current!Puerto!Rican!enrollees!in!the!top!part!of!the!distribution!
of!income2to2poverty!ratio!by!subgroup.!We!applied!take2up!rates!from!a!matrix!of!age2
group!by!insurance!coverage!and!disability!status.!
!
Summary)of)Limitations)to)the)Models)
!
First,!despite!our!attempts!to!produce!reliable!coverage!estimates!with!the!ACS/PRCS,!
there!still!may!be!measurement!errors,!which!could!introduce!bias!into!our!estimates!at!
the!national,!state,!within2state,!and!subgroup!levels.!!In!particular,!measurement!error!
!
7!
in!estimates!of!Medicaid!eligibility!and!participation!may!result!from:!the!use!of!the!
ACS’s!and!PRCS’s!income!data,!which!collects!annual!rather!than!monthly!income,!and!
thus!does!not!align!with!eligibility!determination!procedures!(and!which!could!
miscalculate!eligibility!for!those!whose!income!fluctuates!from!month!to!month);!the!
misreporting!of!income!or!other!information,!such!as!immigration!status,!used!in!
determining!eligibility;!and!the!systematic!underreporting!of!income!in!survey!data!
(Moore,!Stinson,!and!Welnick!2000),!which!could!lead!to!overstating!the!number!of!
eligible!and!understating!their!participation.!The!possible!inclusion!of!enrollees!in!
restricted2benefit!Medicaid!coverage!or!local!public!plans!(which!are!not!modeled!in!this!
simulation)!among!those!classified!as!having!Medicaid!coverage!could!also!bias!the!
results.!!!
!
Modeling!eligibility!for!adults!is!much!more!difficult!than!for!children!for!a!number!of!
reasons:!first,!the!eligibility!rules!are!more!complex!for!adults!and!thus!harder!to!derive!
from!summary!reports!and!state!manuals;!second,!the!ACS!and!the!PRCS,!like!other!
surveys,!does!not!contain!the!detail!needed!to!correctly!capture!important!elements!of!
all!the!major!eligibility!pathways!for!adults!(e.g.,!pregnancy!status,!legal!disability!status,!
income!disregards!related!to!child!support,!medical!spending!used!to!calculate!spend2
down!for!medically!needy!eligibility,!or!duration!of!enrollment!or!income!history!to!
determine!transitional!medical!assistance![TMA]!and!related!eligibility);!and!third,!some!
states!offer!coverage!for!adults!that!is!less!comprehensive!in!scope!than!full!Medicaid!
benefits.!!While!extensive!efforts!were!made!to!collect!information!on!the!different!
rules!for!each!state!and!to!marshal!all!the!relevant!information!in!the!ACS,!eligibility!in!
states!that!have!additional!pathways!that!are!not!captured!in!our!model!(particularly!for!
adults)!may!be!understated.!Limitations!in!the!survey!indicators!could!also!introduce!
error;!for!instance,!states’!determinations!of!disability2related!eligibility!use!criteria!
other!than!the!indicators!of!functional!limitations!available!on!the!ACS/PRCS,!and!the!
surveys!lack!data!to!determine!whether!custodial!parents!meet!child!support!
cooperation!requirements!that!could!preclude!them!from!Medicaid!eligibility!(Roberts!
2003).!Thus,!some!of!the!adults!who!appear!in!our!model!to!be!eligible!might!not!qualify!
when!the!more!detailed!information!on!their!characteristics!is!taken!into!account.!
While,!taken!together,!we!believe!the!limitations!in!our!study!may!bias!upward!our!
participation!rates!and!downward!our!estimates!of!the!number!of!uninsured!adults!who!
are!eligible!but!not!enrolled,!the!direction!and!extent!of!bias!are!not!known.!
!
!
!
!
!
8!
!
References!!
!
Boudreaux,!M.,!J.!Y.!Ziegenfuss,!P.!Graven,!M.!Davern,!and!L.!Blewett.!2011.!Counting!
Uninsurance!and!Means2Tested!Coverage!in!the!American!Community!Survey:!A!
Comparison!to!the!Current!Population!Survey.!Health'Services'Research!46(1):210–231.!
!
Centers!for!Medicare!and!Medicaid!Services.!2012.!“State!Health!Official/State!Medicaid!
Director!Letter!RE:!Conversion!of!Net!Income!Standards!to!MAGI!Equivalent!Income!
Standards.”!http://www.medicaid.gov/Federal2Policy2
Guidance/downloads/SHO12003.pdf.!
!
Cohen!Ross,!D.,!A.!Horn,!R.!Rudowitz,!and!C.!Marks.!2008.!Determining!Income!Eligibility!
in!Children’s!Health!Coverage!Programs:!How!States!Use!Disregards!in!Children’s!
Medicaid!and!SCHIP.!Washington,!D.C.:!Kaiser!Com2!mission!on!Medicaid!and!the!
Uninsured.!http://!www.kff.org/medicaid/upload/7776.pdf.!
Cohen!Ross,!D.,!M.!Jarlenski,!S.!Artiga,!and!C.!Marks.!2009.!A!Foundation!for!Health!Re2!
form:!Findings!of!a!50!State!Survey!of!Eligibility!Rules,!Enrollment!and!Renewal!
Procedures,!and!Cost2!Sharing!Practices!in!Medicaid!and!CHIP!for!Children!and!Parents!
During!2009.!Washington,!D.C.:!Kaiser!Com2!mission!on!Medicaid!and!the!Uninsured.!
http://www.kff.org/medicaid/upload/8028.pdf.!
Department!of!Health!and!Human!Services.!2012.!“Medicaid!Program;!Eligibility!
Changes!Under!the!Affordable!Care!Act!of!2010;!Final!Rule.”!Federal!Register!Vol.!77,!
No.!57.!http://www.gpo.gov/fdsys/pkg/FR22012203223/html/201226560.htm.!
———.!2013.!“ASPE!Research!Brief:!Modified!Adjusted!Gross!Income!(MAGI)!Income!
Conversion!Methodologies.”!
http://aspe.hhs.gov/health/reports/2013/MAGIConversions/rb_magicon.cfm!
Griffin,!D.,!and!T.!Hughes.!2010.!Mixed!Mode!Data!Collection!in!the!American!
Community!Survey.!American!Association!of!Public!Opin2!ion!Research!Conference!
Proceedings,!May!2010,!Chicago,!Ill.!
Heberlein,!M.,!T.!Brooks,!J.!Guyer,!S.!Artiga,!and!J.!Stephens.!2011.!Holding!Steady,!
Looking!Ahead:!Annual!Findings!of!a!502State!Survey!of!Eligibility!Rules,!Enrollment!and!
Renewal!Pro2!cedures,!and!Cost2Sharing!Practices!in!Medicaid!and!CHIP,!2010–2011.!
Washington,!D.C.:!Kaiser!Commission!on!Medicaid!and!the!Uninsured.!
———.!2012.!Performing!Under!Pressure:!Annual!Findings!of!a!502State!Survey!of!
Eligibility,!Enrollment,!Renewal,!and!Cost2Sharing!Policies!in!Medicaid!and!CHIP,!2011–
2012.!Washington,!D.C.:!Kaiser!Commission!on!Medicaid!and!the!Uninsured.!
!
9!
Heberlein,!M.,!T.!Brooks,!J.!Alker,!S.!Artiga,!and!J.!Stephens.!2013.!Getting'into'Gear'for'
2014:'Findings'from'a'50=State'Survey'of'Eligibility',Enrollment,'Renewal,'and'Cost=
Sharing'Policies'in'Medicaid'and'CHIP.!Washington,!DC:!Kaiser!Commission!on!Medicaid!
and!the!Uninsured.!http://ccf.georgetown.edu/wp2content/uploads/2013/01/Getting2
Into2Gear2for22014.pdf.!
Kaiser!Commission!on!Medicaid!and!the!Uninsured.!2010.!Expanding!Medicaid!to!Low2!
Income!Childless!Adults!under!Health!Re2!form:!Key!Lessons!from!State!Experiences.!
Publication!No.!8087.!Washington,!D.C.:!Kaiser!Commission!on!Medicaid!and!the!
Uninsured.!
———.!2011a.!Where!are!States!Today?!Medicaid!and!CHIP!Eligibility!Levels!for!Children!
and!Non2Disabled!Adults.!Publication!No.!79932!02.!Washington,!D.C.:!Kaiser!
Commission!on!Medicaid!and!the!Uninsured.!
———.!2011b.!Explaining'Health'Reform:'The'New'Rules'for'Determining'Income'Under'
Medicaid'in'2014.!Washington,!DC:!Kaiser!Commission!on!Medicaid!and!the!Uninsured.!
No.!8194.!http://www.kff.org/healthreform/upload/8194.pdf.!
Kenney,!G.,!J.!Holahan,!and!L.!Nichols.!2006.!Towards!a!More!Reliable!Federal!Survey!for!
Tracking!Health!Insurance!Coverage!and!Access.!Health!Services!Research!41(3):918–
945.!
Kenney,!G.,!V.!Lynch,!A.!Cook,!and!S.!Phong.!2010.!Who!and!Where!are!theChildren!Yet!
to!Enroll!in!Medicaid!and!the!Children’s!Health!Insurance!Program?!Health!Affairs!
29(10):1920–1929.!
Kenney,!G.,!V.!Lynch,!J.!Haley,!M.!Huntress,!D.!Resnick,!and!C.!Coyer.!2011.!Gains!for!
Children:!Increased!Participation!in!Medicaid!and!CHIP!in!2009.!Washington,!D.C.:!The!
Urban!Institute!and!Robert!Wood!Johnson!Foundation.!
http://www.rwjf.org/files/research/!20110816coveragegainsforkidsfull.pdf.!
Kenney,!G.,!S.!Zuckerman,!L.!Dubay,!M.!Huntress,!V.!Lynch,!J.!Haley,!and!N.!Anderson.!
2012.!Opting!in!to!the!Medicaid!Expansion!under!the!ACA:!Who!Are!the!Uninsured!
Adults!Who!Could!Gain!Health!Insurance!Coverage?!Robert!Wood!Johnson!Foundation!
Quick!Strike!Series,!No.!78.!Princeton,!N.J.:!The!Robert!Wood!Johnson!Foundation.!
http://!www.rwjf.org/coverage/product.jsp?id574697.!
Lynch,!V.,!and!G.!Kenney.!2011.!Improving!the!American!Community!Survey!for!Studying!
Health!Insurance!Reform.!Proceedings!of!the!10th!Conference!on!Health!Survey!
Research!Methods,!April!2011,!Atlanta,!Ga.!Hyattsville,!Md.:!Department!of!Health!and!
Human!Services.!
Lynch,!V.,!G.!M.!Kenney,!J.!Haley,!and!D.!M.!Resnick.!2011.!Improving!the!Validity!of!the!
!
10!
Medicaid/CHIP!Estimates!on!the!American!Community!Survey:!The!Role!of!Logical!
Coverage!Edits.!Submitted!to!the!U.S.!Census!Bureau.!
http://www.census.gov/hhes/www/hlthins/!
publications/Improving%20the%20Validity%20!of%20the%20Medicaid2
CHIP%20Estimates%!20on%20the%20ACS.pdf.!
Lynch,!V.,!M.!Boudreaux,!and!M.!Davern.!2010.!Applying!and!Evaluating!Logical!
Coverage!Edits!to!Health!Insurance!Coverage!in!the!American!Community!Survey.!
Suitland,!Md.:!U.S.!Census!Bureau,!Housing!and!Household!Economic!Statistics!Division.!
Lynch,!V.!and!D.!Resnick.!2013.!“Results!of!a!Record!Check!of!Edits!to!Health!Insurance!
Coverage!in!the!American!Community!Survey”.!Washington,!DC:!Urban!Institute!Report!
for!the!U.S.!Census!Bureau.!!
!
Lynch,!V.,!L.!Dubay,!J.!Haley,!and!G.!Kenney.!2013.!“Estimating!the!Gap!Between!the!
Needs!for!Children!and!Health!Coverage!and!Benefits!Through!Implementation!of!the!
Affordable!Care!Act”.!Washington,!DC:!Urban!Institute.!
!
Mach,!A.,!and!B.!O’Hara.!!2011.!Do!People!Really!Have!Multiple!Health!Insurance!Plans?!
Estimates!of!Nongroup!Health!Insurance!in!the!American!Community!Survey.!American!
Statistical!Association!2011!Proceedings.!
!
Moore,!J.!C.,!L.!L.!Stinson,!and!E.!J.!Welniak.!2000.!Income!Measurement!in!Surveys:!A!
Review.!Journal!of!Official!Statistics!16:331–361.!
National!Center!for!Health!Statistics,!Division!of!Health!Interview!Statistics.!2005.!2004!
National!Health!Interview!Survey!(NHIS)!Public!Use!Data!Release!Survey!Description.!
Hyattsville,!Md.:!National!Center!for!Health!Statistics.!
http://www.cdc.gov/nchs/data/nhis/srvydesc.pdf.!
National!Immigration!Law!Center.!2011.!Table:!Medical!Assistance!Programs!for!
Immigrants!in!Various!States.!http://www.nilc.org/pubs/guideup2!dates/med2services2
for2imms2in2states22011207.pdf.!
Passel,!J.,!and!D.!Cohen.!2009.!A!Portrait!of!Unauthorized!Immigrants!in!the!United!
States.!Washington,!D.C.:!Pew!Hispanic!Center.!
Resnick,!D.!2013.!“Imputing!Undocumented!Immigrant!Status!in!the!American!
Community!Survey”.!Washington,!D.C.:!Urban!Institute.!
Ruggles,!S.,!T.!J.!Alexander,!K.!Genadek,!R.!Goeken,!M.!Schroeder,!and!M.!Sobek.!2010.!
Integrated!Public!Use!Microdata!Series:!Version!5.0![Machine2readable!database].!
Minneapolis,!Minn.:!University!of!Minnesota.!
!
11!
Sullivan,!J.!2010.!Expanding!Coverage!for!Recent!Immigrants:!CHIPRA!Gives!States!New!
Options.!Washington,!D.C.:!Families!USA.!http://familie2!
susa2.org/assets/pdfs/chipra/immigrant2coverage.pdf.!
Turner,!J.,!and!M.!Boudreaux.!2010.!Health!Insurance!Coverage!in!the!American!
Community!Survey:!A!Comparison!to!Two!Other!Federal!Surveys.!Washington,!D.C.:!
National!Academies!Press.!
U.S.!Census!Bureau.!2012.!American!Community!Survey!Response!Rates:!Data:!United!
States.!http://www.census.gov/acs/www/methodology/response_rates_data/.!
!
!
!
!
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!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
i
!The!Indian!Health!Service!(IHS)!is!not!typically!counted!as!health!insurance!coverage!
because!of!limitations!in!the!scope!of!available!services!and!geographic!reach!of!IHS!
facilities.!!
ii
!We!benchmarked!our!estimates!to!the!NHIS!because!both!surveys!measure!point2in2
time!coverage!status!and!because!of!other!desirable!measurement!properties!of!the!
health!insurance!coverage!estimates!of!the!NHIS!(Kenney,!Holahan,!and!Nichols!2006).!
iii
!According!to!Urban!Institute!tabulations!of!data!from!the!2008!National!Health!
Interview!Survey.!!
iv
!The!2008!American!Community!Survey!includes!1.4!million!children!with!employer2
sponsored!or!other!coverage!who!were!also!reported!to!have!Medicaid/CHIP!at!the!time!
of!the!survey.!The!difference!between!our!adjusted!state!Medicaid/CHIP!total!and!the!
respective!administrative!total!varies!across!states;!for!more!than!half!of!the!states,!the!
difference!is!less!than!10!percent.!
v
!Family2level!characteristics!used!in!determining!eligibility,!such!as!income,!are!based!
on!the!grouping!of!family!members!to!align!with!Medicaid!rules.!Statistics!on!‘‘family’’!
characteristics!in!this!paper!are!based!on!the!more!straightforward!grouping!of!family!
members!who!would!be!eligible!for!the!same!private!insurance!plan,!known!as!the!
health!insurance!unit!(HIU).!!
vi
!The!model!takes!into!account!disregards!for!child!care!expenses,!work!expenses,!and!
earnings!in!determining!eligibility,!but!does!not!take!into!account!child!support!
disregards!because!data!on!such!amounts!were!not!available.!!
vii
!The!model!assigns!eligibility!type!hierarchically,!and!cases!are!classified!by!the!first!
pathway!for!which!they!are!eligible.!For!instance,!if!an!SSI!recipient!gets!classified!as!
eligible!through!the!SSI!pathway,!that!person!would!be!classified!as!eligible!through!
disability2related!coverage!even!if!the!individual!also!met!the!qualifications!for!Section!
1931!coverage.!!
viii
!We!do!not!model!eligibility!for!restricted!Medicaid!benefits,!such!as!family!planning!
services!or!emergency!services.!As!defined!in!this!paper,!limited!coverage!is!more!
!
12!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
comprehensive!than!such!restricted2benefit!coverage.!The!limited!programs!modeled!
here!all!cover,!at!the!least,!hospitalizations!and!doctor!visits.!
ix
!Estimates!from!the!March!2010!CPS2ASEC!that!use!the!same!eligibility!rules!and!cover!
roughly!the!same!time!period!are!similar;!a!total!of!9!million!adults!with!Medicaid!
coverage!do!not!appear!eligible!for!comprehensive!Medicaid!services!through!the!main!
pathways!that!are!simulated,!1.5!million!of!whom!are!eligible!for!limited!coverage,!and!
3.2!million!of!whom!are!imputed!eligible!(authors’!communication!with!Christine!Coyer,!
January!27,!2012).!
x
!We!also!produced!additional!sets!of!participation!estimates!to!show!the!impact!of!
excluding!children!who!appear!to!have!Medicaid!as!well!as!other!coverage!(so2called!
wrap2!around!coverage)!and!of!excluding!children!not!found!to!be!eligible.!The!pattern!
of!findings!reported!in!our!reports!with!these!additional!estimates!in!terms!of!variation!
across!states!and!subgroups.!
xi
!Furthermore,!asset!tests!will!be!eliminated!in!Medicaid!under!the!ACA;!however,!since!
few!states!have!asset!tests!for!children’s!Medicaid!eligibility,!these!should!not!have!a!
large!impact!on!overall!eligibility.!
!
13!