Subjects that are parts of Siberia.
According to Great Soviet Encyclopedia (and many other Soviet and Russian sources) (dark green):
Urals Federal District (brown border)

1.Khanty-Mansi Autonomous Okrug
2.Kurgan Oblast
3.Tyumen Oblast
4.Yamalo-Nenets Autonomous OkrugSiberian Federal District (blue border)

5.Altai Krai
6.Altai Republic
7.Buryat Republic
8.Irkutsk Oblast
9.Kemerovo Oblast
10.Republic of Khakassia
11.Krasnoyarsk Krai
12.Novosibirsk Oblast
13.Omsk Oblast
14.Tomsk Oblast
15.Tuva Republic
16.Zabaykalsky KrayFar Eastern Federal District(yellow border)

17.Sakha (Yakutia) Republic 	YakutskFederal subjects of Siberia in wide sense—according to other sources (Britannica, etc.)(light green):
Far Eastern Federal District:

18.Amur Oblast
19.Chukotka Autonomous Okrug
20.Jewish Autonomous Oblast
21.Kamchatka Krai
22.Khabarovsk Krai
23.Magadan Oblast
24.Primorsky Krai
25.Sakhalin OblastUrals Federal District:

26.Chelyabinsk Oblast
27.Sverdlovsk OblastRed line is the Pacific-Arctic drainage divide  (approximately)

Based on the map of Russia with merged subjects (01.03.2008).
Map of Russian subjects, 2008-03-01.svg
derivative work: S .B. Odin
Map of Russian subjects, 2008-03-01.svg: original:user:fremantleboy
edits: Lokal_Profil