Reciting the blessing after the second washing:
After awakening in the morning one is to wash his hands [near his bed] without saying a blessing, immediately proceed to use the bathroom, and [immediately] after leaving the bathroom he is to wash his hands a second time and recite the blessing of Al Netilas Yadayim. This is [immediately] followed by Asher Yatzar [and Elokaiy Neshama].
If one does not need to use the bathroom: If one does not currently need to use the bathroom, and will not do so for a very long while, then he is to say the blessing immediately [after washing near his bed]. [Nevertheless one is to try to go to the bathroom immediately after awakening, even if he does not feel the urge to do so, in order to be able to recite Al Netilas Yadayim and Asher Yatzar after washing upon leaving the bathroom.]
Not to delay the blessing until one goes to Shul: One is not to delay the blessing of Al Netilas Yadayim and Asher Yatzar until he arrives at Shul and is rather to recite it upon washing after the bathroom, as explained above. One may not repeat the blessing when he arrives at Shul and doing so is a blessing in vain. This applies even for the Chazan which desires to repeat the blessings for the sake of the congregation.
After awakening in the morning one is to wash his hands [near his bed] without a blessing, immediately proceed to use the bathroom, and [immediately] after leaving the bathroom he is to wash his hands a second time and recite the blessing of Al Netilas Yadayim. This is [immediately] followed by Asher Yatzar [and Elokaiy Neshama]. If one does not need to use the bathroom he is nevertheless to try to do so. If he is unable, then he is to say the blessing of Al Netilas Yadayim and Asher Yatzar [and Elokaiy Neshama] after the first washing which is done near his bed.
May one delay the second washing with the blessing until he goes to Mikveh?
One is to wash with a blessing of Al Netilas Yadayim and recite Asher Yatzar/Elokaiy Neshama right after he goes to the bathroom after washing near his bed, as stated in Halacha 8B. One is not to delay this washing with a blessing until after he immerses in a Mikveh.
If one is a Baal Keri: Even if one is a Baal Keri he is to nevertheless follow the above procedure and wash after using the bathroom, and recite Al Netilas Yadayim and Asher Yatzar. He is not to delay the blessings until after Mikveh. [Regarding Elokaiy Neshama and the remainder of Birchas Hashachar-See Chapter 8 Halacha 9 in Q&A!] Nevertheless there are those that are accustomed not to say any blessings until after they have immersed and purified themselves from their state of Keri. One who follows this custom must proceed to the Mikveh immediately upon awakening and wash with a blessing right after Mikveh.
Practically if one washed and did not say the blessing, until when may the blessing be said?
 6/1; Siddur; Kitzur SH”A 2/7; Ketzos Hashulchan 2/9; Ben Ish Chaiy Vayeitzei 2
Ruling of Rama and M”A: The Rama 4/1 records that one is to recite the blessing of Asher Yatzar after reciting the blessing over morning washing even if he did not use the bathroom. The M”A 4/1 brings that the Arizal [Peri Eitz Chaim Shaar Habrachos 1] writes to recite the washing blessing immediately after the morning washing and then go to the bathroom and say Asher Yatzar. The M”A ibid concludes that in his opinion one should first use the bathroom in order to say Asher Yatzar right away and avoid a question [of whether Asher Yatzar may be recited without bathroom use]. It is unclear from the M”A conclusion as to when the blessing of Al Netilas Yadayim should be said.
Ruling of Admur in 6/1: Admur in 6/1 rules like the M”A ibid that one who desires to avoid the question should immediately go to the bathroom after the morning washing and after the bathroom he is to wash his hands a second time and say Asher Yatzar. Admur then concludes: “It is proper not to recite the blessing of Netilas Yadayim until after the second washing that he performs after he leaves the bathroom. This especially applies if one needs to use the bathroom upon awakening, in which case it is forbidden to recite a blessing.” Thus Admur clearly rules that the blessing of Netilas Yadayim is to be differed until after the second washing. If he does not need to use the bathroom [but does so anyways] then it is merely proper to differ the blessing until after the bathroom, and if he needs to use the bathroom then he must differ the blessing until the washing done after the bathroom.
Ruling of Admur in Siddur: In the Siddur Admur records this ruling with slight nuances: “Initially when a person awakens in the morning and is in need of using the bathroom and he thus intends to do so right away, then he is to [wash hands near his bed and] delay reciting the blessing until he leaves the bathroom. If however he does not currently need to use the bathroom and will not do so for a very long while, then he is to say the blessing immediately [after washing near his bed].” It seems from the Siddur that the delay of the blessing is dependent on whether he needs the bathroom, unlike the ruling of 6/1 which rules that even if one does not need to use the bathroom it is proper to delay the blessing. In truth however there is no contradiction as Admur in 6/1 is saying that if one does not feel an urge to go to the bathroom, but is able to if he tries, then he is to do so and it is proper to delay the blessing until afterwards. If however he feels an urge to use the bathroom then he must do so prior to saying the blessing. The Siddur is not arguing on this point. Therefore the Siddur states that only if he does not feel the urge to use the bathroom and is not planning to do so for many hours should he say the blessing right away. This extra wording implies that even if he does not feel the urge to use the bathroom he is nevertheless to try to do so as is implied from 6/1. This is also implied from the Siddur’s wording of “initially” as opposed to “must”. Thus the ruling of the Siddur and Shulchan Aruch do not contradict and in turn complement each other. However Tzaruch Iyun from Siddur which says “Lechatchilah when one awakens and needs to use the bathroom, and has in mind to do so immediately, he should delay saying the blessing until he leaves the bathroom” Vetzaruch Iyun, as in the Shulchan Aruch it says that its forbidden to say the blessing if he needs to go to the bathroom, and not just that Lechatchilah its best to do so. Thus why does Admur mention about him planning to go immediately, which implies that if he has to go but plans to push it off then he should say the blessing after the 1st washing? Vetzaruch Iyun!
The reason for delaying the blessing until after the second washing done after the bathroom: It is forbidden to recite a blessing if one feels the urge to use the bathroom. [Admur 6/1] This is learnt from the verse “My innards will bless G-d”, thus implying that one needs to empty his innards of feces and urine prior to saying a blessing. [Kitzur Shulchan Aruch 2/7, brought in Ketzos Hashulchan 2/9] Thus if one feels an urge to use the bathroom upon awakening it is forbidden for him to recite the blessing of Al Netilas Yadayim until he relieves himself. He must therefore wash near his bed without a blessing and then rewash after the bathroom with a blessing. Furthermore even if he does not feel the urge to use the bathroom and thus he may say the blessing right away, it is nevertheless better to first use the bathroom and then wash again and only then say the blessing. [6/1] Admur does not state the reason behind this delay. Seemingly the reason for this delay is in order to proximate the blessings of Asher Yatzar to Al Netilas Yadayim so they are said one after the other. [See Peri Megadim 4 A”A 1] The reason for this is perhaps because these two blessings share the same reason for being said, as they are both said as a result of awakening as a new creation. [See Admur 4/1 and 6/1; M”A 4/1] Alternatively it is because Asher Yatzar is said as a result of washing hands, as before washing one is not allowed to touch the orifices and hence after washing we thank Hashem for that ability. [Darkei Moshe; M”A 4/2; Peri Megadim 4 A”A 1 explicitly writes this as the reason of why Asher Yatzar should be said immediately after the blessing for washing.] Alternatively there is no need to proximate the two blessings and the reason for the delay is in order to say the blessing of Al Netilas Yadayim as close as possible to prayer without needing to go to the bathroom in between. [see Basra 4/1 first opinion] Alternatively it is done in order so the blessing of Al Netilas Yadayim be in proximity with some prayer. [See Piskeiy Teshuvos 4 footnote 12]
 Admur in 6/1 writes “One who desires to avoid the question is to be careful to go to the bathroom immediately [Teikaf Umiyad] after the morning washing.” Likewise in the Siddur Admur writes “And he intends to immediately use the bathroom.” This wording is taken from the M”A 4/1.
 Peri Megadim 4 A”A 1
 Siddur; Ketzos Hashulchan 2/9
Other Opinions: Piskeiy Teshuvos [4/2] writes it is customary of all Jewry to not say the blessing during the initial washing and rather it is delayed to a second washing. It is however difficult to say that this is the custom in a case that one does not need to use the bathroom at all and as clearly rules Admur in the Siddur.
 This additional wording implies that if one assesses that he will need to go in the near future then he is to delay the blessing until the washing of after leaving the bathroom. Alternatively Admur is saying that even one who does not currently have an urge to go to the bathroom, but is able to push himself to do so, then he is to go to the bathroom immediately after the first washing. This is similar to the implied ruling in 6/1. See background!
 See previous footnote and background.
 6/2-5; Siddur; Shulchan Menachem 1/6; Sefer Hasichos 1944 p. 20; See “Other Poskim” for all the opinions that rule like Admur.
Background of Admur:
Admur ibid records two customs with regards to when one should say the blessing over washing his hands; right after the washing or in Shul.
Custom of saying in Shul [6/2-4]: Some have the custom that when they will be going to shul immediately upon awakening they delay saying the blessings of Al Netilas Yadayim until they enter the shul, and they then say the blessing together with all the other morning blessings. The reason for this is because the main reason for washing in the morning is in order to sanctify oneself for service of G-d like a Kohen which would sanctify his hands prior to his service. Now since the main service of G-d is to praise Him and to pray before him, therefore one may [delay to] say the blessing over washing hands [until directly] prior to prayer, as if not for the prayer there would be no need to wash hands. [6/2 based on Beis Yosef] However even according to this custom the blessing may only be delayed in a situation that immediately after washing hands one goes to shul and begins to immediately recite the morning blessings. It is however forbidden to make an interval, even to learn Torah or recite psalms, and certainly not to do other [mundane] matters. Therefore if one wants to make an interval between the washing and the morning blessings such as he plans [not to go immediately to shul after the washing or] to recite psalms or selichot prior to reciting the morning blessings then he needs to be careful to say the blessing immediately after the washing. [6/3] Thus those communities which only begin saying these blessings of Netilas Yadayim and Asher Yatzar after reciting psalms or selichot in shul are not doing the proper thing, and they need to be protested, as they are making a long interval which is improper. [6/4]
Custom to say the blessings immediately after washing at home: Others have the custom to always say the blessings of Netilas Yadayim and Asher Yatzar in their house immediately after washing, [even if they plan to go to shul and pray immediately after the washing]. They then recite the remaining blessings at Shul, omitting the blessings they already said at home. [6/5]
Final Ruling of Admur: Practically, this latter custom is the proper custom, and one should therefore do accordingly, as in truth all blessings are really to be said prior to the action, and it is only due to the fact that one is prohibited from saying G-d’s name before washing that we say the blessing afterwards. Thus one needs to try as much as possible to say the blessing as close as possible to the washing. [6/5]
Other Poskim: The following Poskim rule like Admur that the blessing is to be said immediately after awakening [after the second washing and not in Shul]: Makor Chaim [of Rav Chaim Hakohen] based on Kabala that the impurity does not leave until after the blessing; Shaareiy Teshuvah 6/4; Kaf Hachaim 6/2; Kaneh Bosem 2/3; Shulchan Hatahor 4/1 in name of Chozeh of Lublin; See Piskeiy Teshuvos 4/2 footnote 11. However there are Poskim that rule one is to delay the second washing and blessing until he is ready to pray Shacharis, in which case he is to go to the bathroom and then wash with a blessing. The reason for this is because if he says the blessing after using the bathroom upon awakening and then uses the bathroom again prior to Davening, his original washing is nullified according to the Rosh. [Chayeh Adam 7/6; Maaseh Rav of Gr”a; brought in M”B 4/4] To note that in the Siddur of Admur and Shulchan Aruch 6/8 it is evident that he completely negates this claim of the Chayeh Adam as he rules that even if one plans to return to sleep a set sleep in middle of the night he may say the blessing of Netilas Yadayim the first time, even though according to the Rosh it is invalidated with the sleep. [See Yagdil Torah 6 p. 49 notes of the Kudinaver on Alter Rebbe’s Shulchan Aruch]
Opinion of Mishneh Berurah: In the Biur Halacha “Afilu” the M”B questions the ruling of the Chayeh Adam stating that according to the Rashba one seemingly must say the blessing as soon as possible after awakening. In conclusion he sides like the Chayeh Adam that one is not to recite the blessing until prior to Shacharis. Before beginning Shacharis he is to go to the bathroom and then wash hands with a blessing. This is done in order to fulfill one’s obligation even in accordance to the Rosh and Rambam which require one to wash with a blessing prior to every prayer. [Biur Halacha “Afilu” in name of Chayeh Adam] See Kaneh Bosem 2/3 who questions this ruling; Halichos Shlomo 2/23 which upholds his opinion; Piskeiy Teshuvos 4/2 footnote 11.
 6/4 implies that also Asher Yatzar needs to be said immediately upon using the bathroom, or awakening, as otherwise it’s an interval.
 This is considered a blessing in vain as in today’s times everyone is an expert and knows how to say the blessings and therefore does so himself. If the Chazan does not want to swerve from the custom of the Shul to say these blessings by the Amud then he may not say these blessings at home after washing and is to say it in Shul without making any interval between the washing and the blessing. Thus he may not learn or say Tehillim in between and certainly may not do other mundane matters. [6/4]
 6/2-5; Siddur; Shulchan Menachem 1/6; Sefer Hasichos 1944 p. 20
 So I received from Harav Yosef Simcha Ginzberg and other Rabbanei Anash; Darkei Chaim Veshalom 9: When the Munkatcher would immerse Tevilas Ezra he would say the blessings of Al Netilas Yadayim and Asher Yatzar beforehand while Elokaiy Neshama he would say in his mind until after he immersed; See also Sefer Hamamarim 5672 Vol. 2 P. 737
 Mishmeres Shalom 2/1 and so is the custom of many Chassidim; See Maor Vashmesh Emor regarding not even thinking Torsah beforehand; See Shulchan Melachim [Tevilas Ezra] 20; Based on Ketzos Hashulchan 12 footnote 9 there is no interval actually being done between the washing and the blessing being that the blessing is being said on the second washing.
 As rules the opinion in Admur 6/2; Shulchan Hatahor 4; Ketzos Hashulchan 2/4; Regarding saying the blessing after Shacharis-see Halacha 2 Q&A.
Other Opinions: The Shaareiy Teshuvah 4/4 rules that if an interval took place one is to wash without a blessing as the impurity has already been removed and hence the blessing has been lost. The Ketzos Hashulchan 2 footnote 16 argues on this ruling and so questions the Birchas Habayis 32/5; Minchas Elazar 2/44.
 See Biur Halacha 4 “Afilu”; Ketzos Hashulchan 12 footnote 9