Availability of adult dental plans in the Affordable Care Act Marketplaces

Abstract

The Affordable Care Act Marketplaces may improve access to dental insurance, but little is known about the availability of such coverage. We used data from state and federal Marketplace sources to describe the availability of adult dental plans, including standalone dental plans (SADP) and those embedded in medical plans. We also examined the characteristics of counties with limited dental insurer participation (with two or fewer insurers) and those that experienced a net loss of SADP insurers between 2016 and 2023. We found that in 2023, at least one SADP was offered in every state, and 36 states offered embedded dental plans. Most counties (63.6%) had access to more than five insurers offering adult dental plans, while approximately 4% had only one insurer offering adult dental plans. Counties in state-based Marketplaces, rural areas, and dentist shortage areas were more likely to be limited dental insurer participation counties. The net loss of SADPs between 2016 and 2023 was more common in state-based Marketplaces and disadvantaged counties. Our findings can inform future policies to improve the dental insurance Marketplace and access to affordable dental care.

INTRODUCTION

Dental coverage increases access to dental services, improves health outcomes, and reduces preventable emergency department hospital visits.^1,2 Even after the implementation of the Affordable Care Act (ACA), nearly 68.5 million adults still lacked dental coverage in 2023.³ Unlike pediatric dental benefits, which are considered part of the ACA’s essential health benefits⁴, adult dental benefits remain optional under the ACA.

Since their creation in 2014, the ACA health insurance Marketplaces have been a key source of coverage for millions of adults. The passage of the American Rescue Plan Act in 2021 and the Inflation Reduction Act in 2022 have further enhanced Marketplace premium subsidies, improving access to health coverage. Marketplace enrollment has increased significantly among low-income households, particularly among Black and Hispanic groups, as well as individuals earning greater than 200% of the federal poverty level, who are primarily White.⁵ However, dental coverage for adults remains less common and not well studied. Since the start of 2024, about 21.3 million individuals have enrolled in coverage through Marketplaces,^6,7 and with the end of the Medicaid continuous enrollment policy, more low-income adults are expected to turn to Marketplaces for affordable coverage after disenrolling from Medicaid.

Health insurance plans in the Marketplaces have assigned metal levels⁸ and cost-sharing limits and must provide coverage for essential health benefits, but this does not include adult dental benefits. However, the CMS new rule will allow states, starting in January 2027, to expand essential health benefits to include adult dental coverage.⁹

Adult dental plans can be offered as a standalone dental plan (SADP) or embedded within a medical plan, and Marketplace consumers may opt to purchase or not purchase dental coverage. Embedded dental plans have actuarial values according to the five defined metal levels for health plans (platinum, gold, silver, bronze, and catastrophic), whereas SADPs offer only two levels of coverage (low or high actuarial value). Furthermore, there are differences in benefit generosity and cost-sharing. Embedded dental plans usually provide coverage only for preventive services and may come with a high deductible. On the other hand, SADPs typically provide more comprehensive coverage with a lower deductible.¹⁰

Although the Marketplaces offer dental coverage and can reduce financial burden for many adults, little is known about adult dental plans’ availability and geographic distribution in the Marketplace. In this study, we compiled data from various federal and state sources to describe the availability and distribution of adult dental plans (both SADP and embedded) in 2023, as well as trends in SADPs from 2016 to 2023. We then examined the characteristics of counties with limited dental insurer participation and counties that experienced a net loss in the number of SADP insurers between 2016 and 2023.

STUDY DATA AND METHODS

Data sources

Marketplace adult dental plans.

As of 2023, 30 states used federally facilitated Marketplaces, 18 used state governments (state-based Marketplace), and 3 relied partially on the federal government (state-based Marketplace-federal platforms) to operate their Marketplace.¹¹ Hereafter, we categorize states into two groups – state-based Marketplaces (SBMs), and federally-facilitated Marketplaces (FFMs, combining the federally facilitated Marketplaces and state-based Marketplace-federal platforms). For information on SADPs, we obtained data from the U.S. Department of Health and Human Services (HHS)¹² and the Centers for Medicare and Medicaid Services (CMS) Health Insurance State-based Exchange.¹³ HHS provides annual plan-level SADP data for federally facilitated Marketplaces from 2014 to 2023. The CMS Health Insurance State-based Exchange provides annual county-level SADP data on Marketplace plans offered through state-based Marketplace from 2016 to 2023. For completeness of data, we limited all SADP analyses to 2016 to 2023. The HHS data on the FFMs included 501 SADPs in 2016 and 590 SADPs in 2023. Meanwhile, CMS data on SBMs had 188 SADPs in 2016 and 229 SADPs in 2023.

For embedded dental plans, we used data from the Robert Wood Johnson Foundation’s Health Insurance Exchange (HIX) Compare 2023 database, which provides information on adult dental plans embedded in medical plans from all Marketplaces.¹⁴ The embedded dental data are available for all 50 states and the District of Columbia, from 2014 to 2023. However, there were missing data for adult dental plans for 15 states (AK, CA, HI, IA, MA, MD, ME, MN, ND, NJ, NM, RI, SD, VT, WA) and the District of Columbia. Therefore, we only used data on embedded dental plans from 2023 and directly collected information from each state’s Marketplace on the availability of embedded adult dental plans for the 15 missing states. The HIX 2023 database included 1,622 embedded adult dental plans from 2,285 counties.

County characteristics.

Using county Federal Information Processing Series (FIPS) codes, we merged Marketplace adult dental plans data with several county-level demographic data sources. We used data from the 5-year American Community Survey (ACS) 2021 estimates to obtain data on the racial and ethnic composition of each county to examine how racism has affected the geographic distribution of socioeconomic resources, which can result in lower insurers entry in counties that are disproportionately home to racialized minority groups.¹⁵ To determine areas with a shortage of dentists at the county level and examine how network provider adequacy affects insurer participation, we obtained data from HRSA’s Area Health Resources Files for 2021–2022.¹⁶ Data on the county’s rurality was obtained from the National Center for Health Statistics (NCHS).¹⁷ We used the area deprivation index (ADI) version 3.1 from the Neighborhood Atlas through the University of Wisconsin to measure neighborhood socioeconomic disadvantage.^18,19 The ADI is a multidimensional measure of neighborhood disadvantage that is composed of 17 measures of education, income, housing quality, and poverty using data from the ACS to rank census block groups from 1% (least disadvantaged) to 100% (most disadvantaged). Finally, we included 2023 data on states’ health insurance Marketplace type from the Kaiser Family Foundation.¹¹

SADP enrollment.

We used data from the Marketplace Open Enrollment Period for adults aged 18 to 64 in federally facilitated Marketplaces, as data for enrollment in state-based Marketplaces is unavailable.²⁰ Because data on enrollment in dental plans were unavailable prior to 2018, we limited our enrollment analyses to the period from 2018 to 2023.

Variables

Our unit of analysis is the county. To calculate the percentage of the Black and Hispanic populations in each county, we used the Z score to standardize these percentages. The ADI data are provided at the block group level,¹⁹ therefore, we calculated the weighted population mean for each county by aggregating block-group ADI.^21,22 We sorted counties according to ADI quartiles, with the first quartile (least disadvantaged counties) as our reference group. We defined the dentist shortage area as counties with a population-to-provider ratio of at least 5,000 to 1, according to the Health Professional Shortage Area (HPSA) designations.²³ Rural counties were defined using the NCHS urban-rural classification, which includes micropolitan and non-core counties.²⁴

Our first outcome was limited dental insurer participation, which we defined as a binary variable equal to one if a county had two or fewer insurers offering adult dental plans in the Marketplace in 2023. Our second outcome was a net loss in number of SADP insurers from 2016 to 2023, which we defined as a binary variable equal to one if the number of SADP insurers in a county decreased by one or more insurers from 2016 to 2023 and zero if the county had no change or gained an insurer during that period.

Statistical analysis

First, we examined the characteristics of Marketplace dental plans that offer adult dental benefits in 2023 at the state, county, and plan level according to the type of offering (embedded vs SADP). Second, we created county-level maps to examine the geographic variation of insurer counts. We examined the geographic variation for embedded adult dental plans and SADPs, both combined and stratified. Third, we examined trends in insurer participation for SADPs from 2016 to 2023. Fourth, we examined the enrollment in SADP in federally facilitated Marketplaces for adults aged 18 to 64. We calculated the dental plan take-up rate among Marketplace enrollees, which is the percentage of Marketplace enrollees who selected an SADP, and the Pearson correlation coefficient to examine the association between the number of SADP offerings and enrollment.

Finally, we estimated a separate linear probability regression model to examine the characteristics of counties with limited insurer participation (two or fewer) in the Marketplace offering adult dental plans and those that had a net loss of SADP insurers from 2016 to 2023. The regression models included state-level covariates (Marketplace type) and county-level covariates (rurality, dentist shortage area, percentage of Black and Hispanic populations, and ADI).

All analyses were performed in Python 3.11²⁵ and ArcGIS 3.2.0.²⁶

Limitations

First, we could not examine trends in embedded dental plans over time because data on embedded adult dental plans were incomplete before 2022. Nevertheless, we provided current estimates of all adult dental plan availability in the Marketplace for 2023, and comprehensive data on changes in SADPs over time. Second, we assessed the relationship between the availability of SADPs and enrollment only in federally facilitated Marketplaces because state-based Marketplaces do not publish their SADP enrollment data, and we lacked complete plan data on embedded dental plans beyond 2023. Third, our regression analyses are correlational, and cannot clearly identify cause-and-effect relationships between our variables. Fourth, we did not consider variations across plans in premiums and out-of-pocket cost-sharing in this analysis that warrant future research. Fifth, while analyzing plan quality would be informative, the currently available data does not allow for a rigorous analysis since SADPs do not provide ratings, and embedded dental plans offer overall ratings for the health plan rather than specifically for dental plans.

RESULTS

Geographic variation in the distribution of Marketplace dental plans

Exhibit 1 presents the characteristics of SADPs and embedded adult dental plans offered in the Marketplace in 2023. All states offered SADPs, with an average of 5.8 insurers per county. However, only 86.7% of states with federally facilitated Marketplaces and 38.9% of state-based Marketplaces offered embedded adult dental plans, with an overall average of 2.2 insurers per state and 1.8 insurers per county.

Exhibit 1.

Characteristic of Marketplace dental plans that offer adult dental benefits in 2023

Characteristic	Standalone dental plans	Embedded	Botha
	n	n	n
Characteristic
State-level
Marketplace type
Federally-facilitated Marketplace, (n=30)	30	26	26
State-based Marketplace, (n=18)	18	7	7
State-based Marketplace-Federal Platform, (n=3)	3	3	3
Average number of insurers by state, [min, max]	5.3	2.2	1
Average number of plans by state, [min, max]	16.1	45.1	---b
County-level
Marketplace type
Federally-facilitated Marketplace, (n=2,205)	2,205	1,809	1,809
State-based Marketplace, (n=694)	694	328	328
State-based Marketplace-Federal Platform, (n=244)	244	148	148
Average number of insurers by county, [min, max]	5.8	1.8	1
Average number of plans by county, [min, max]	17.4	31.7	---b
Plan-level
Total number of insurers	267	76	2
Total number of plans	819	1,622	---b
Plan type
Preferred Provider Organization (PPO)	702	186	---b
Health Maintenance Organization (HMO)	55	911	---b
Point-Of-Service plan (POS)	0	127	---b
Exclusive Provider Organization (EPO)	48	398	---b
Indemnity	14	0
Plan metal level
Platinum	---b	27	---b
Gold	---b	252	---b
Silver	---b	1115	---b
Expanded-bronze	---b	153	---b
Bronze	---b	69	---b
Catastrophic	---b	6	---b
High actuarial	323	---b	---b
Low actuarial	496	---b	---b

Source. source. Authors’ analysis of data from the Robert Wood Johnson Foundation’s Health Insurance Exchange Compare 2023 database, the U.S. Department of Health and Human Services, and the Centers for Medicare and Medicaid Services.

NOTES:

^aoffering both standalone dental plans and embedded dental plans.

^bNot applicable

A total of 819 SADPs were offered nationally. Of 18,736 health plans on the Marketplace, 1,622 (8.7%) offered embedded adult dental plans in 2,285 (72.7%)counties across 36 states. 267 insurers offered SADPs, 76 insurers offered embedded dental plans, and only two insurers offered both embedded and SADPs. During our study period, 1,975 counties were classified as rural, all of which had access to SADPs, and 71.6% rural counties had access to embedded adult dental plans.

Most SADPs (85.7%) were Preferred Provider Organizations plans (PPO), while most embedded dental plans (56.2%) were Health Maintenance Organizations plans (HMO). Most SADPs were “low actuarial value” plans (60.6%), and silver plans were the most offered embedded dental plans (68.7%).

Exhibit 2 displays the geographic distribution of insurers offering adult dental plans across the U.S. Marketplace in 2023 – combining both embedded plans and SADPs. Most counties, 63.6% (representing 67.4% of nonelderly adults), had more than five insurers offering adult dental plans; however, nearly 4% (representing 0.8 of nonelderly adults) had only one insurer offering adult dental plans.

Exhibit 2.

Number of Marketplace insurers that offer adult dental benefits in 2023 per county

Source. Authors’ analysis of data from 1) the Robert Wood Johnson Foundation’s Health Insurance Exchange Compare 2023 database; 2) the U.S. Department of Health and Human Services; 3) and the Centers for Medicare and Medicaid Services. Map includes insurers for standalone dental plans and embedded dental plans.

Our stratified analyses (online appendix Exhibit 1)²⁷ indicated that for embedded adult dental plans, 32.3% of counties had two insurers (representing 34.1% of nonelderly adults) and 29.6% had only one insurer (representing 15.7% of nonelderly adults). For SADPs, 43.5% of counties (representing 39.2% of nonelderly adults) had 6 to 10 insurers, and 6.5% had only one insurer (representing 1.4% of nonelderly adults).

The number of insurers offering adult dental plans varied widely across states. For instance, in 2023, only one insurer offered SADPs in South Dakota and Vermont with statewide option, while in Texas, 13 SADP insurers were available. New York had the highest number of insurers offering embedded adult dental plans (7) (online appendix Exhibit 2).²⁷

Some counties had extremely high numbers of plan offerings. For instance, nearly 5.3% of nonelderly adults lived in counties with 37 SADPs, and 0.6% of nonelderly had access to more than 80 embedded dental plans.

Some insurers dominated the dental Marketplace. For instance, SADP Delta Dental was available to more than 89% of the nonelderly adult population, and embedded Ambetter insurer was available to 48% of the nonelderly adult population (online appendix Exhibit 3).²⁷

Changes in SADPs from 2016 to 2023

Between 2016 and 2023, the average number of insurers per county offering SADPs remained nearly constant. However, the average number of plans offered per county increased from 13.9 to 17.4, indicating increased numbers of average plan offerings by each insurer. During this period, the average number per county of high actuarial plans remained nearly the same (from 6.4 to 6.7), while the average number of low actuarial plans significantly increased from 7.8 to 11.4 (online appendix Exhibit 4).²⁷

The number of counties with a single Marketplace insurer offering SADPs increased from 3.1% (representing 2.0% nonelderly adults) in 2016 to 6.5% (representing 1.4% nonelderly adults) in 2023.

Enrollment in SADPs

In 2023, nearly 1.2 million adults enrolled in SADPs from federally facilitated Marketplaces. Enrollment declined after 2018 and increased again in 2023 (online appendix Exhibit 5).²⁷ The dental plan take-up rate among Marketplace enrollees decreased from 16.2% in 2018 to 11.5% in 2023. Older adults aged 55 to 64 had the highest enrollment rates in SADPs, ranging from 24.9% in 2018 to 27.6% in 2023. There was a weak, positive correlation between the number of SADPs offered and enrollment in federally facilitated Marketplaces (r=0.168 p<.001).

Characteristics of counties with limited insurer participation

In 2023, 9.2% of counties (representing 3.1 % of nonelderly adults) had two or fewer insurers offering adult dental benefits.

Our regression results (Exhibit 3) show that state-based Marketplace counties were more likely to have a limited number of dental insurers than federally facilitated Marketplaces (+19.1 percentage points; P< 0.001). Counties in rural and dentist shortage areas were more likely to have a limited number of insurers (+8.3; P<0.001 and +3.7 percentage points; P<0.005, respectively). However, counties with a higher percentage of Black residents and the most deprived (fourth quartile), compared to the least deprived counties, were −2.7 (P<0.001) and −4.7 (P<0.005) percentage points less likely to have a limited number of dental insurers.

Exhibit 3.

Estimated relationships between county characteristics, limited dental insurer participation in 2023, and experience of a net loss of SADP insurers from 2016 to 2023

	Limited insurer Participation in 2023a		Net loss of SADP Insurers from 2016 to 2023b
	n=290 counties		n=882 counties
	Coefficient	(SE)	Coefficient	(SE)
State-level characteristics
Marketplace type
Federally-facilitated (Ref.)	----c	----c	----c	----c
State-based	0.191***	0.012	0.331***	0.020
County-level characteristics
Rurality
Urban (Ref.)	----c	----c	----c	----c
Rural	0.083***	0.012	−0.005	0.018
Dentist shortage area
No (Ref.)	----c	----c	----c	----c
Yes	0.037**	0.012	0	0.019
Racial and ethnic composition
Black residents (%)	−0.027***	0.005	−0.008	0.008
Hispanic residents (%)	−0.007	0.005	−0.025**	0.008
Area deprivation index (ADI)
ADI-1 (least deprived) (Ref.)	----c	----c	----c	----c
ADI-2	0.021	0.014	0.047**	0.023
ADI-3	−0.018	0.015	0.087***	0.024
ADI-4 (most deprived)	−0.047**	0.017	0.123***	0.027

Source. Authors’ analysis of data from the Robert Wood Johnson Foundation’s Health Insurance Exchange Compare 2023 database, the U.S. Department of Health and Human Services, and the Centers for Medicare and Medicaid Services. Note. SADP= standalone dental plans

^aLimited insurer participation in 2023 defined as two or fewer insurers that offer adult dental benefits in 2023.

^bNet loss in the number of SADP insurers defined as decrease by one or more insurers from 2016 to 2023.

^cNot applicable.

Results are from linear probability regression models.

^**p < 0.05

^***p < 0.001

Characteristics of counties that experienced a net loss of SADP insurers from 2016 to 2023

Between 2016 and 2023, 28.1% of counties (representing 25.4% of nonelderly adults) in 30 states experienced a reduction in the number of SADP insurers (Exhibit 4).

Exhibit 4.

Changes in standalone dental plans insurer participation from 2016 to 2023

Source. Authors’ analysis of data from the U.S. Department of Health and Human Services and the Centers for Medicare and Medicaid Services. Note. In 2016, standalone dental plans were not offered in the states of MA and WA.

Our regression results (Exhibit 3) show that state-based Marketplace counties, compared to counties using the federally-facilitated Marketplace, were +33.1 percentage points (P<0.001) more likely to lose one or more SADP insurers. Counties with a higher percentage of Hispanic population were also less likely to lose SADP insurers (−2.5 percentage points; P<0.005). Disadvantaged counties (second, third, and fourth quartile) were more likely to lose SADP insurers than the least disadvantaged counties (+4.7, +8.7, and +12.3 percentage points, respectively).

DISCUSSION

Our study provides an overview of the national landscape of adult dental plans offered in the ACA individual health insurance Marketplaces. In 2023, at least one SADP was offered in every county, with an average of nearly 6 offerings; embedded dental plans were somewhat less common, available in 73% of U.S. counties (in 36 states) with an average of 1.8 plans per county in those offering such plans. There was wide variation in the availability of dental plans and insurers across counties. Rural counties, dentist shortage areas, and state-based Marketplaces were more likely to have two or fewer insurers offering adult dental plans. We found that 882 counties, of which 64.6% were rural, experienced reductions in the number of SADP insurers from 2016 to 2023. We also found that counties that had a net loss of SADP insurers over time were more likely to be associated with state-based Marketplaces and the disadvantaged counties.

One key set of implications comes from the broader availability of SADPs than embedded plans. There are significant differences in benefits, provider availability, and cost-sharing between SADPs and embedded adult dental plans. For instance, SADPs have separate premiums and do not qualify for federal premium subsidies, while embedded plans must meet the ACA Marketplace requirement to limit out-of-pocket costs and can use a single deductible towards medical and dental services. These differences in cost-sharing are significant for low-income individuals eligible for financial assistance through the Marketplace. Although there is little evidence on how premiums differ between SADPs and embedded dental plans for adults, SADP premiums among children are generally much higher than embedded plans.²⁸ Choosing between embedded plans and SADPs can also impact access to dental services. Due to difficulties securing dentist participation in SADPs, these plans are exempt from meeting the HHS network adequacy requirement to establish a network of dental providers in areas with a shortage of dentists, unlike embedded dental plans.²⁹ However, more than 57 million Americans live in areas with a shortage of dentists,³⁰ which raises concerns about whether SADPs can meet their members’ dental needs in a timely manner.

Prior studies on medical plans in the Marketplace have shown that greater competition between insurers can lead to a decrease in premium costs^31,32 and enhance the quality of plans offered.³³ Although we did not examine how insurers’ participation in the Marketplace affects changes in premiums or enrollment, our findings indicate that in 2023, nearly 30% of counties had only a single embedded insurer, and 6.5% had only a single SADP insurer. In addition, almost 28% of counties experienced a decrease in the number of SADP insurers between 2016 and 2023. This trend, if continued, could lead to more areas with single insurers, which may increase premium costs and reduce enrollment for residents in those counties.^31,34 Because health plan quality ratings are not common for SADPs,³⁵ we could not determine whether plans available in counties with limited dental insurers in our analyses are from high-quality insurers. However, we found that the metal rating of these plans was mixed. Reporting plan rating and network provider information could encourage more people to enroll in SADPs, incentivizing new insurers to enter the ACA Marketplaces and expand their service areas, ultimately enhancing competition. In addition, starting in 2025, CMS will allow states to include adult dental benefits as essential health benefits⁹ which may further expand access to dental coverage in the Marketplaces.

We also found that the number of dental plans offered in the Marketplace varies significantly across counties and in some cases is so high as to potentially overwhelm consumers who are considering purchasing coverage. For instance, residents in some counties had as many as 37 SADPs and 88 embedded adult dental plan options to choose from. Previous research has shown that having excessive plan options can lead to confusion and poor insurance decisions.³⁶ In 2023, CMS adopted a standardized plan policy for health insurers offering plans through the federal platform to simplify plan structures and improve comparability across options;^37,38 however, this requirement does not currently apply to SADPs. The benefit design of dental plans is generally complex, with significant variability in the level of coverage, premiums, and cost-sharing according to actuarial values. While all plans typically cover preventive services, there is wide variation in deductibles, copayments, and waiting periods before coverage starts (examples of SADP and embedded plans are presented in the online appendix Exhibit 6).²⁷ Policymakers may want to consider adopting a standardized plan requirement for Marketplace dental coverage to facilitate and improve consumer understanding of their options.

Counties with a high proportion of Black residents were less likely to have limited insurer participation in 2023, while counties with a high proportion of Hispanic residents were less likely to experience a net loss of SADP insurers. These findings may be due to insurers being more inclined to participate in densely populated urban areas (online appendix Exhibit 7)²⁷, where Black and Hispanic populations are more concentrated ³⁹ and less likely to participate in rural areas.⁴⁰ Therefore, the association between racial demographics and insurance availability may be attributed to the urban-rural distribution of these populations.

Conclusion

Nearly 21.3 million individuals million individuals now have insurance through the ACA Marketplaces.⁷ Yet, knowledge about dental coverage for this population is limited. We find that options for dental coverage in the Marketplace vary widely by county. While every county has access to at least one adult dental plan, counties in rural areas, those with a shortage of dentists, and in state-based Marketplaces are more likely to have limited insurers. Plan offerings in some counties are sparse, while in others they are so numerous as to be potentially overwhelm would-be beneficiaries. Standalone dental plans – which may be less affordable to beneficiaries than dental benefits embedded in health plans – are the predominant coverage type. With the new CMS rule allowing states to include adult dental benefits as essential health benefits in 2027, our findings can inform states to improve the dental insurance Marketplace and ensure everyone can access affordable dental care.