Circumcision
Circumcision is very important to most branches of Judaism, with over 90% of male adherents having the procedure performed as a religious obligation. The basis for its observance is found in the Torah of the Hebrew Bible, in Genesis chapter 17, in which a covenant of circumcision is made with Abraham and his descendants. Jewish circumcision is part of the "brit milah" ritual, to be performed by a specialist ritual circumciser, a "mohel", on the eighth day of a newborn son's life, with certain exceptions for poor health. Jewish law requires that the circumcision leaves the glans bare when the penis is flaccid. Converts to Conservative and Orthodox Judaism must also be circumcised; those who are already circumcised undergo a symbolic circumcision ritual. Circumcision is not required by Judaism for one to be considered Jewish, but some adherents foresee serious negative spiritual consequences if it is neglected.
Brit milah
A "Milah L'shem giur" is a "Circumcision for the purpose of conversion". In Orthodox Judaism, this procedure is usually done by adoptive parents for adopted boys who are being converted as part of the adoption or by families with young children converting together. It is also required for adult converts who were not previously circumcised, e.g. those born in countries where circumcision at birth is not common. The conversion of a minor is valid in both Orthodox and Conservative Judaism until a child reaches the age of majority (13 for a boy, 12 for a girl); at that time the child has the option of renouncing his conversion and Judaism, and the conversion will then be considered retroactively invalid. He must be informed of his right to renounce his conversion if he wishes. If he does not make such a statement, it is accepted that the boy is halakhically Jewish. Orthodox rabbis will generally not convert a non-Jewish child raised by a mother who has not converted to Judaism.