Siman 336

It is written: "And he shall surely provide for his healing" – from here [we learn] that the Torah gave permission to a physician to heal (Bava Kamma 85a). That is to say: so that you should not say, since the wisdom of medicine is a mere estimation, if so, perhaps he will cause damage? For this, the Torah gave permission to a physician to heal. And since permission was given, it follows that it is an obligation upon him to heal. And behold, we desecrate Shabbat for this when it is necessary to perform the healing, even if its performance involves several primary categories of labor, if the patient is in danger. And it is included in the category of pikuach nefesh, and one who abstains from this – behold, he is a shedder of blood. And even if [the patient] has someone else to heal him, for not from everyone does a person merit to be healed. And anyone who is diligent in pikuach nefesh – behold, he is praiseworthy.

However, it is forbidden to engage in medicine unless he is expert and has permission from the beit din. And nowadays, he must be certified by the government, that he has permission to give medicines to the sick. And also, there must not be one greater than him there, for if not so, when he causes damage—behold, he is a shedder of blood. And if he healed without permission from the beit din and the government—he is liable for payments even if he is expert if the patient was damaged by his hand, and he must pay out money for medicines. And all the more so if he died by his hand—behold, this is like one who kills a soul intentionally. But if he healed with permission and erred and caused damage—he is exempt by the laws of man. And he is liable by the laws of Heaven if it was through his negligence and he did not examine well, for if he examined—he has no sin at all, since it is a mitzvah to heal. And the sage already said: "The error of the physician is the intention of the Creator." And if he died through his medicines and it became known to him that he erred—behold, he goes into exile because of him, when there is room to attribute that he caused it to him through negligence or that he did not examine well. But without this, it seems to me that he is not liable for exile, for how is he worse than a father who strikes his son or a teacher his student, who are exempt from exile? (So it seems to my humble opinion to explain the Tosefta and the words of the Ramban that the Tur and the Shulchan Aruch brought, and see Beit Yosef. And be precise and you will find it easy.)

Regarding the matter of the physician's fee, the Tur wrote in the name of the Ramban that it is permitted to take payment for lost time and exertion. However, a fee for teaching is forbidden, as it is the restoration of his body, and the Torah said, "and you shall return it to him" — to include the restoration of his body. And we say regarding the performance of mitzvot: Just as I am for free, so too you are for free. Therefore, a fee for wisdom and teaching is forbidden. However, a fee for exertion and a fee for lost time is permitted. Thus far his words. That is to say: a fee for wisdom and teaching is when he says to him: "Take such-and-such medicine." But when he goes to the sick person, it is a fee for exertion. And similarly, when he writes for him to the apothecary to give such-and-south — it is a fee for exertion and is permitted.

One who possesses medications and the sick person needs them – it is forbidden for him to raise their price more than is appropriate. Not only this, but even if they agreed to a high price for them due to the urgency of the hour, because these medications were not found in the possession of another – he is only entitled to their value. However, if he stipulated a high fee for the doctor – he is obligated to give it to him, for he sold him his wisdom, and this does not have a fixed value. And even though it is a mitzvah upon him to heal him, for any mitzvah that is cast upon everyone, if it happened to come to one person and he did not want to fulfill it except for such and such an amount of money – it is not retrieved from his hand. Thus ruled the Tur and the Shulchan Aruch in section 3 (Shulchan Aruch Yoreh Deah 336, 3). And so too regarding medications, if he already received the money – it is not retrieved from his hand (the Gaon Rabbi Akiva Eiger). And from the language of the Tur and Shulchan Aruch it is implied that specifically when the doctor already received the money. But some say that even if he has not yet received it – they are obligated to pay him even afterward (Bach and Shach, subsection 7). However, it is certainly so that if he traveled to the sick person in another city – there is no law and there is no judge, for they are obligated to pay everything that they agreed upon with him. And see Choshen Mishpat siman 264.