The graphs above display a breakdown of the population by parent organization and stars rating and have three major takeaways:
1) Kaiser has almost all of its population in 5 star plans.
2) United, Aetna, and Humana have a median star rating of around 4.
3) Organization other than the big six listed above are more likely to have lower rated plans.
A follow-up blog will be posted once the 2018 population breakdown by organization and star rating is released.