Mysteries of the Maryland ACA Marketplace, cont.

As I noted on Oct. 3, Maryland Health Connection, the state's ACA exchange, sent me enrollment data indicating that Maryland may have the highest "CSR takeup rate" in the country. That is, in 2015, Maryland private plan buyers whose incomes qualify them for Cost Sharing Reduction (CSR) subsidies, which are available only with silver plans, chose silver and access the benefit at market leading rates. In Maryland, 86% of CSR-eligible buyers chose silver, compared to a national average of about 76%. That's doubtless in large part because Maryland cloned the web interface of the Connecticut exchange, which does an excellent job steering CSR-eligibles toward silver.

There are some peculiarities in the Maryland data, though, and they're thrown into sharper relief by the raw numbers of silver plan enrollees at each income level, which I did not have when I posted last week. Chief among them is a relatively huge number of buyers, 22%, with incomes low enough to qualify them for Medicaid, unless they're lawfully present non-citizens not yet eligible for Medicaid because they've been in the country less than five years.

Let me quote from the prior post to lay out the mysteries, then we'll take a look at what the raw numbers show.

The first oddity is a very low level of silver selection among buyers with incomes in the 100-138% FPL range.  That is likely a very small number of enrollees [NO! -- see below], since eligibility for subsidies generally begins at 139% FPL, and those below that level qualify for Medicaid.  The exception is legally present immigrants and residents subject to a 5-year bar from Medicaid eligibility -- they are eligible for tax credits from 0-400% FPL.  In states that expanded Medicaid, about 2% of enrollees are under 100% FPL; the percentage from 100-138% FPL would likely be smaller.

The more striking oddity is a very high silver selection rate in the 200-250% FPL band, and comparatively low takeup at 138-150% FPL.  In most states, CSR takeup is highest at the lowest eligible income levels and drops off steeply in higher income bands.

Most states don't break out metal level selection by income level, but among those that do, the highest silver selection percentage I've seen previously for the 200-250% FPL band is 64%, in Connecticut (which, again, created the web design that Maryland has adopted).

Okay, here's the raw numbers for metal level selection in each income band:

FPL & METAL	CAT	BRZ	SLV	GLD	PLT	Total
<100 fpl="" nbsp="" td="">	234	1,097	10,286	467	333	12,417
≥100 - ≤138%	294	5,454	6,611	1,848	791	14,998
>138 - ≤150%	67	210	2,286	47	37	2,647
>150 - ≤200%	45	479	5,443	135	89	6,191
>200 - ≤250%	171	3,132	24,249	607	548	28,707
>250 - ≤300%	222	4,315	13,909	1,236	585	20,267
>300- ≤400%	295	4,205	6,734	1,396	574	13,204
> 400%	231	3,578	3,273	1,370	758	9,210
Unknown	1,238	6,740	3,495	3,066	1,606	16,145
Total	2,797	29,210	76,286	10,172	5,321	123,786

Re the high silver selection in the 200-250% FPL band, and the relatively low takeup at 138-150%: the raw numbers highlight the fact that Maryland is the wealthiest state in the country. In Maryland, 23% of buyers are in the 200-250% FPL band versus 14% in  the 37 states using healthcare.gov. Conversely, in Maryland 14% of buyers have incomes from 100-150% FPL, compared to 38% in all healthcare.gov states, and 20% in healthcare.gov states that expanded Medicaid, where (as in Maryland, subsidy eligibility begins at 139% FPL.* That difference makes Maryland's high takeup all the more astonishing, as CSR is a relatively negligible benefit at 200-250% FPL (see the prior post), while the premium for the benchmark silver plan is set to take anywhere from 6.3% to 8.1% of the buyer's income. That's a lot -- and bronze beckons with a lower price tag.

Much stranger, though, is the huge bulge of buyers in the 100-138% FPL band, and their lower silver selection rate. Citizens at that income level are not eligible for subsidies in Maryland -- they're eligible for Medicaid. The only subsidy-eligible buyers at that income level are lawfully present immigrants and residents subject to the 5-year bar from Medicaid eligibility. We don't know what percentage of buyers in other states are immigrants with incomes in the 100-138% FPL range. But we do know that 3% of buyers in the hc.gov states have incomes under 100% FPL, and that legally present noncitizens are the only people eligible for subsidies at that income level. Moreover, the very low silver level selection in the 100-138% FPL band in Maryland -- just 44% -- suggests that most of these buyers are not subsidy-eligible, or are not accessing their subsidies. Under 138% FPL, silver plan premiums are capped at 2% of income., so silver is very attractive. The super-high gold and platinum selection in the 100-138% FPL band (17% combined, versus 10% nationally) is also striking.

Compounding the mystery, the percentage of buyers with incomes below 100% FPL -- 10% -- is also huge -- and in this population, silver plan selection is more in line with expectations. At the same time it's well below that of Connecticut and New York, two states that have published or supplied me with data making comparison possible. In New York, 97% of buyers under 150% FPL chose silver; in Connecticut, 89% of buyers under 200% FPL did so.

It would appear that in Maryland, most buyers under 100% FPL are legally present noncitizens, and most buyers in the 100-138% FPL band are not. Enrollee percentages in both bands are anomalously large. I can't read the riddle, and I've asked the Maryland exchange folks for their insights. I'll update if/when they shed any light.

As of 2013, 9.8% of Maryland's population (842,250) was foreign-born, but half of that population had become citizens, and 4.3% of the state population was unauthorized immigrants. That would not seem to leave a huge pool of lawfully present immigrants subject to the 5-year bar.
--
*  Corrected, 10/9 - originally had 44% here, the total for hc.gov states that refused the Medicaid expansion. I've also added the more relevant comparison, to the expansion states.