In Hidayah, the main book of Hanafi Fiqh, it says that Jizya, (and by extension, dhimmi status) is leveled on the Ahli Kitaab and Fire Worshippers, the first because of an order to Allah to that effect in Surah Tawbah, Ayat 29, and the second because it is proven in a Hadith that Rasoolullah SAWS took jizya from a Fire worshipper. And according to Imam Abo Hanifa, Jizya may also be leveled on a non-Arab idolatoror, but according to Imam Shafee, fighting them is mandatory, because the original order in the Ayat is: fight them.We know that it is permissible to level Jizya in the case of the Ahli Kitaab by the Quraan itself, and in the case of fire-worshippers by Hadeeth, but in all others the original order applies. And Imam Abo Hanifa's point is that enslaving idolatorors is permissible, so levelling Jizya on them is also permissible, because in each cases his life is spared, so he will earn and pay jizya to muslims and his living expenses will be from his earnings.
From what I understand from this, according to Imam Shafee, jizya is only leveled on Ahli Kitab with the sole exception being Fire-Worshippers. Thus Agnostics and Atheists do not qualify for dhimmi status and they would either be killed or enslaved.
Imam Abo Hanifa's position seems to indicate, though he does not clearly state it, that dhimmi status could be granted to an Atheist or Agnostic. His use of the term 'idolatorors' appears to cover all other religions. Furthermore, the logic behind his arguement is that if you can make a person a slave, you can also make him a dhimmi. I don't actually know whether Agnostics and Atheists can be enslaved, but if they can, they should be granted dhimmi status as well.
I am attaching a scan of the page of Hidayah from which I took my information