Unearthing a corpse and reburying in a different plot:
It is forbidden to unbury a body for burial in a different area with exception to the cases to be listed. This applies even if the body has already decomposed and only the bones remain. This applies even if one desires to make room for another Kever, or to make space [for the city]. This applies even if his current burial ground is repugnant and one desires to rebury him in a more pleasant burial ground. This applies even if one desires to bury the person elsewhere for reasons relating to his honor.
The following, however, are the mitigating circumstances in which unearthing, and reburial are permitted:
- Family plot: If he is not currently buried in his families plot and will be reburied near his ancestors [or family, or spouse] then he may be unearthed and reburied. [Some Poskim rule that this allowance only applies if he will be buried in the family plot in which the members of the family are all buried. If, however, there is no set family plot and every family member is buried elsewhere, then the allowance to bury one near the other does not apply. This allowance does not apply if the person is buried in Eretz Yisrael and they desire to rebury him in a family plot in the Diaspora.]
- Eretz Yisrael: If he is currently buried in the diaspora and will be reburied in Eretz Yisrael, then he may be unearthed and reburied there. [This applies even if a Tnaiy was not made. Nonetheless, the widespread custom is to initially make a Tnaiy even when one intends to rebury the deceased in Eretz Yisrael. In all cases, a Rav is to be contacted prior to making any decision.]
- Tnaiy: If he was originally buried [by the Chevra Kadisha, or children] on condition to be unearthed and reburied elsewhere, then he may be unearthed and reburied. [This applies even after many years. Practically, the custom is to delay the unearthing and reburial in such a case for 12 months, as explained in B.]
- Worry of gentiles: If there is worry that gentiles will remove the body from its current burial grounds, then he may be unearthed and reburied.
- Jewish burial: If he was buried amongst gentiles and will be reburied in a Jewish cemetery then he may be unearthed and reburied.
- Damage to grave: If there is worry that the grave will be [plowed over or] destroyed by flood, then he may be unearthed and reburied.
- Illegal burial: If the person was buried in the area without permission, and was not a Meis Mitzvah, then he may be unearthed and buried elsewhere.
- Public damage: If the grave is causing damage to the public, such as if it is near a road, it may be unearthed and buried elsewhere, even if it was legally buried in its current location.
*In all cases that it is permitted to unearth a grave-see Chapter 31 Halacha 11 regarding if the grave is later permitted in benefit.
Temporarily unearthing without intent to rebury elsewhere: It is forbidden to dig open a grave once it is closed even if one plans to re-bury it right away. This applies even if the heirs desire to open the grave for monetary related purposes. [It is disputed amongst Poskim as to whether the body may be unearthed for identification purposes for the sake of releasing his wife from Aguna status, or for the sake of having the children say Kaddish. It is likewise disputed amongst Poskim as to whether one may unearth the body if one of the Tachrichin garments were not placed on him. If a child was buried without a circumcision, it is permitted for the child to be unearthed and circumcised.]
B. Likkut Atzamos-The process of unearthing and reburying the body:
Throughout the process of unearthing the remains, utmost respect must be kept to the remains and the process.
When: The body is to only be unearthed after the flesh has decomposed and the skeleton remains without it being identifiable. [This, however, only refers to if the son is unearthing his father’s remains, while by other people, it is not necessary to wait until decomposition of the body. Nonetheless, usually, the Chevra Kadisha will wait 12 months to transfer the body after it is buried.]
Caring for the remains: The skeletal remains of the unearthed body must be kept intact, without breaking them, or tearing any of their sinews that attach them together. The bones may be removed using one’s hands. When unearthing more than one body simultaneously, they are to be placed in different caskets, and are not to be mixed up.
Who: A son should avoid collecting his father’s bones, although from the letter of the law, it is permitted for him to do so. A Kohen may not unearth the remains of his father. Those unearthing, transporting, and reburying the body, are exempt from all Mitzvos. One is not allowed to be stringent and perform the commands.
C. Mourning customs followed on the day of unearthing and reburial:
The act of unearthing a body and reburying it elsewhere, carries various laws of mourning for the relatives. [This applies even if the unearthed body still contains flesh, such as it did not decompose. If, however, the body is unearthed with the casket and is reburied with the casket, it is disputed if the mourning laws apply.] On the day of the unearthing the seven relatives are to follow all the laws of Shiva [with exception to a wife who remarried]. The mourning lasts until the nighttime of that day of the unearthing, even if the remains were yet to be reburied. The Aninus laws are not followed at all in this process [and hence they may eat meat and drink wine]. [However, the relatives are exempt from all Mitzvos until the remains are reburied.] Keriah must be reperformed by the relatives on the day of the unearthing. A limited form of comforting and Seudas Havraah takes place on the day of reburial. If a relative heard about the unearthing on a later date, even the next day, he does not follow any mourning laws. If, however, he heard about it on that same day, then the mourning laws apply even if he did not witness it. [Nonetheless, there is no requirement to inform relatives of the unearthing, and on the contrary, one is to avoid doing so.]
 Michaber 363:1; See Darkei Chesed 23; Pnei Baruch 40; Nitei Gavriel Vol. 2 chapter 94
 The reason: As unburying and reburying the body causes confusion to the soul, as they fear the day of judgment. The known term of “rest in peace” is disrupted when the body is unearthed. [Shach 363:1; Taz 363:1]
Unearthing a limb top bury with the body: It is permitted to unearth a limb of a body for the sake of burying it together with the body. [See Nitei Gavriel Vol. 2 94:3 in name of Rav Akiva Eiger]
 Michaber 363:3
 Michaber 363:1; See Igros Kodesh 22:131, printed in Shulchan Menachem 5:260
 Shach 363:2 in name of Darkei Moshe
 Michaber ibid
 Kneses Yechezkal 43; Chasam Sofer Y.D. 331; See Nitei Gavriel Vol. 2 94:4-7 and footnote 4
 Maharsham 3:343; See Nitei Gavriel Vol. 2 94:5
 The reason: As a person desires to be buried near his ancestors [Michaber ibid] and this is done in his honor. [Shach 363:2]
 Maharam Eish Y.D. 121; See Nitei Gavriel Vol. 2 94:6
 Gesher Hachaim; Yabia Omer 6:31; Nitei Gavriel Vol. 2 94:20
 Michaber ibid; See Chasam Sofer Y.D. 334; Seridei Eish 2:100; See Igros Kodesh 17:333, printed in Shulchan Menachem 5:259 where a dispute erupted regarding whether to move the deceased to Eretz Yisrael, and the Rebbe forwarded them to a Rav to answer. Nonetheless, the Rebbe’s leaning approach was to have him moved to Eretz Yisrael. See also Igros Kodesh 22:408, printed in Shulchan Menachem 5:259, that the custom is to permit moving to Eretz Yisrael; See also Igros Kodesh 18:306 [The common denominator of all these answers of the Rebbe is that a) A Rav is to Pasken on whether it should be moved. b) It is permitted to do so, in face of a need.]
 So I received from various members of Chevra Kadisha; See Igros Kodesh 17:333, printed in Shulchan Menachem 5:259, for a case where a Tnaiy was made to rebury in Eretz Yisrael
 See all three letters of Rebbe ibid
 Michaber ibid; See Nitei Gavriel Vol. 2 94:8-11 for various details of the Tnaiy
 Chasam Sofer 6:37; Nitei Gavriel Vol. 2 94:9
 Igros Moshe Y.D. 2:157
 Chacham Tzvi 106, brought in Pischeiy Teshuvah 363:1
 Michaber ibid; See Chasam Sofer 353; Pischeiy Teshuvah 403:1
 Poskim in Nitei Gavriel Vol. 2 94:13
 Michaber 364:2-3; Shach 264:4
 Michaber 364:5
 Michaber 363:7; See Chochmas Adam 158:11; Kitzur SHU”A 199:12; Nitei Gavriel 76:20-23
 See Shivas Tziyion 64-66; Poskim in Pischeiy Teshuvah 363:7; Nitei Gavriel 76:23 footnote 42
 See Chacham Tzvi 47; Pischeiy Teshuvah 363:7; Shut Rav Akiva Eiger Tinyana 17; Nitei Gavriel 76:22
 Bechor Shur Sanhedrin 47; See Poskim in Rav Akiva Eiger 353
 See Michaber 403; Pnei Baruch 40
 Michaber 403:10
 Michaber 403:7
 Decomposition of a body can take anywhere from five to ten years until it becomes skeletal remains.
 Noda Beyehuda Y.D. 89; Maharam Shick 354; Gesher Hachaim 26; Rav Moshe Feinstein; Poskim in Nitei Gavriel Vol. 2 94:8 and footnote 10
The reason: As after the passing of a year, there is not as much fear of judgment for the soul. [ibid]
 Michaber 403:6
 Michaber 403:7-8
 See Michaber 403:8
 Michaber 403:7
 Shach 403:1 in name of Perisha
The reason: As perhaps his father is not whole, and a Kohen may only be Mitame to relatives who are whole. [Shach ibid]
 Michaber 403:9
 Michaber ibid; Beis Hillel 403
 See Michaber 403; Pnei Baruch 40
 Shach 403:2
 See Har Tzevi Y.D. 296; Minchas Elazar 4:12; Gesher Hachaim 12; Chazon Ish 213:1; Pnei Baruch 40:5
 See Pnei Baruch 40:4 if we follow the start of the unearthing or the completion
 Chasam Sofer 355, brought in Pischeiy Teshuvah 403:2
 Michaber 403:1; See Pnei Baruch 40:4
 Shach 403:1
 Rama 403:1
 Chasam Sofer 353; Pischeiy Teshuvos 403:1; Noda Beyehuda Kama 88; Chazon Ish Y.D. 313; Pnei Baruch 40 footnote 2
Other opinions: Some Poskim rule the relatives are not exempt from Mitzvos unless they are physically involved in the unearthing, transporting, or burial. [Igros Moshe Y.D. 3:161; Cheshev Haeifod 2:83; Chelkas Yaakov 2:46; See Pnei Baruch ibid]
 Michaber 403:2
 Michaber 403:3
 Rama 403:5
 Rama 403:5
 Pischeiy Teshuvah 403:1