Yichud with a transgender person?

Question

Suppose there was a man, A, that underwent an operation whereby afterwards A now considers themselves female. Suppose one is generally unclear as to the specifics of the operation, but that A definitely now consider themselves female (e.g female clothing, restroom, etc.).

May a man be in yichud with A? Is it different if one did know the specifics of the operation (i.e is there a specific boundary that has any halachic significance)?

Answer 1

This is an interesting question. I have not an absolute answer but perhaps some matter for right thinking.

1. Androgynos

   Let us have a look at the Tosefta called "Androginos" (known as 4th chapter of Massechess Bikurim) The androginos bears similarities with males and with females. In matter of Ychud he is not allowed to stay alone with men or with women.

   Before we start, we draw attention to the fact that Yichud between two men is allowed. We do not suspect benei Israel for this "לא נחשדו ישראל על כך".

   But if there are strong suspicions, then, automatically, we get a strong prohibition. For example kutim are suspected.

   Here is an extract of our Tosefta:

   ‏ -ב כֵּיצַד שָׁוֶה לָאֲנָשִׁים. מְטַמֵּא בְלֹבֶן, כָּאֲנָשִׁים. וְנוֹשֵׂא, אֲבָל לֹא נִשָּׂא, כָּאֲנָשִׁים. וְאִמּוֹ יוֹשֶׁבֶת עָלָיו בְּדַם טֹהַר, כָּאֲנָשִׁים. ‏ ‏ וְאֵינוֹ מִתְיַחֵד עִם הַנָּשִׁים, כָּאֲנָשִׁים ‏‏. וְאֵינוֹ נִזּוֹן עִם הַבָּנוֹת, כָּאֲנָשִׁים. וּמִתְעַטֵּף, כָּאֲנָשִׁים. וְעוֹבֵר עַל בַּל תַּקִּיף וְעַל בַּל תַּשְׁחִית וְעַל בַּל תִּטָּמֵּא לְמֵתִים, כָּאֲנָשִׁים. וְחַיָּב בְּכָל הַמִּצְוֹת הָאֲמוּרוֹת בַּתּוֹרָה, כָּאֲנָשִׁים: ‏
   He is not entitled to isolate with women, as a men are not.
   

   ג כֵּיצַד שָׁוֶה לַנָּשִׁים. מְטַמֵּא בְאֹדֶם, כַּנָּשִׁים. ‏ ‏ וְאֵינוֹ מִתְיַחֵד עִם הָאֲנָשִׁים, כַּנָּשִׁים ‏ ‏ . וְאֵינוֹ זוֹקֵק לְיִבּוּם, כַּנָּשִׁים. וְאֵינוֹ חוֹלֵק עִם הַבָּנִים, כַּנָּשִׁים. וְאֵין אוֹכֵל בְּקָדְשֵׁי הַמִּקְדָּשׁ, כַּנָּשִׁים. וְאִמּוֹ יוֹשֶׁבֶת עָלָיו בְּדָם טָמֵא, כַּנָּשִׁים. וּפָסוּל מִן הָעֵדוּת, כַּנָּשִׁים. וְאִם נִבְעַל בַּעֲבֵרָה נִפְסַל מִן הַתְּרוּמָה, כַּנָּשִׁים: ‏
   He is not entitled to isolate with men as women are not.

   As says @magicker72 (and I am very grateful to him for the knowledge) the Rambam in Issurei Bia chapter 22, Halacha 11 wrote that men are permitted with tumtum and androgynoss.

   ‏ אַנְדְּרֻגִּינוֹס אֵינוּ מִתְיַחֵד עִם הַנָּשִׁים; וְאִם נִתְיַחַד--אֵין מַכִּין אוֹתוֹ, מִפְּנֵי שְׁהוּא סָפֵק. אֲבָל הָאִישׁ מִתְיַחֵד עִם הָאַנְדְּרֻגִּינוֹס, וְהַטֻּמְטוֹם. ‏
   An androgynos cannot enter into privacy with women. If he does, he is not given physical punishment, because his status is doubtful. A man may enter into privacy with an androgynus or a tumtum.

   
   The Kesef mishney noticed the discrepancy with the Mishna and gives a Teruts.
   But the fact that the Magid Mishne sees on Rambam a citation of the Tosefta is the proof that Rambam had a different version of the Tosefta. In responsa 130 Rabbi Menachem Azaria Mipano wrote, because he is not "spousable for a man", men departed from him. And when they see that he can spouse women, they consider it as a male. And Israeli men are not prohibited to enter in privacy with men. There is a broad spectrum of cases. If the androgynos looks so much like a women, he does not enter in privacy with men. In the Shut he reported a Sugia in Masechet Yebamot: See Mishna Yebamot 8, 6:

   • רַבִּי יוֹסֵי וְרַבִּי שִׁמְעוֹן אוֹמְרִים, אַנְדְּרוֹגִינוֹס כֹּהֵן שֶׁנָּשָׂא בַת יִשְׂרָאֵל, מַאֲכִילָהּ בַּתְּרוּמָה. ‏
     Rabbi Jose and Rabbi Simeon stated: if a priest who was an hermaphrodite married the daughter of an israelite, he confers upon her the right to eat terumah. {this was the first opinion of Rabbi Yosi, but in Berayta he changed his view and said that Androgynos is a being apart, and they do not decide what is his gender}
   • רַבִּי יְהוּדָה אוֹמֵר, ... אַנְדְּרוֹגִינוֹס נוֹשֵׂא, אֲבָל לֹא נִשָּׂא. ‏
     

     Rabbi Judah stated: ... the hermaphrodite may marry [a wife] but may not be married [by a man]. {he is a mal and a man which penetrate it in which way is punished for homosexual intercourse.}

   • רַבִּי אֱלִיעֶזֶר אוֹמֵר, אַנְדְּרוֹגִינוֹס חַיָּבִים עָלָיו סְקִילָה, כְּזָכָר:‏
     

     Rabbi Eliezer stated: [for copulation] with an hermaphrodite the penalty of stoning is incurred as [if he were] a male.{do not agree with Rabbi Yehuda for an intercourse not typically homosexual}

   • If androgynos looks like a woman he is prohibited in Yichud with men,
   • and if he has a penis obviously he is prohibited in Yichud with women.

   And he said this also according to Rambam, and despite he holds that in the version of the Tosefta of the Rambam androgynose's Ychud is allowed.
   

2. Transgender

   • A man who became after an operation similar to a woman is obviously prohibited in Yichud with men.
     In conclusion Ychud with androgynos seems prohibited for a man. I assume that transgenders post op. (men who became anatomically similar to women) and androgynes are roughly equivalents from the point of view of Yichud with men. At first glance this seems obvious.
   • On the other hand, the fact that a male who became after surgery anatomically completely or partially similar to a woman has no right to be alone with women is less obvious. But if he is technically able to have sexual intercourse with a woman, i.e. with erection (not "משמש באבר מת") Yichud is very probably prohibited with women.
   • If male genitalia were removed, he can not have sexual relation with women ("ראוי לביאה או אין ביאתו ביאה"). Therefore Yichud is allowed. (without being directly linked to Halacha, this recalls of the eunuchs harem wardens).
     
     

Answer 2

In ילקוט יוסף, אוצר דינים לאשה ולבת, פרק נ"ו, he writes about gender change surgeries. He initially discusses whether a woman would still need a get if her husband had a gender change surgery done and now considered himself a woman.

He then writes regarding the permissibility of performing such a surgery:

ועכ"פ ברור שאסור לאיש לעשות ניתוח כזה, דמלבד שמפקיע מעצמו מצות האיש (אף שיש לעיין דשמא עדיין חייב בכל המצוות כאיש) גם עובר על איסור סירוס, וא"צ להאריך בזה, ופשוט דהוא אסור ע"פ ההלכה.

In other words, it is forbidden to do the surgery because one will be removing himself from the obligation to do the mitzvos that a man is obligated to do (although he writes that it is possible that he is still obligated to do all the mitzvos incumbent upon men, despite his surgery).

The implication is that by doing the surgery he is effectively a woman and no longer obligated in mitzvos that are specifically for men. Therefore one might thing that Yichud should apply. However he himself is not completely sure as he adds that perhaps the person is still obligated in mitzvos. It is clear however that his primary inclination is that the surgery is effective.

Presumably at least as a safek R' Yosef would rule that Yichud applies.