Tefillin on a Semi-Permanent Toupee

Question: My balding at a young age is having a major effect on my dating and my self-image. I am considering getting a toupee that is glued down to the scalp, which lasts for 3-6 months. Would I have a problem of a chatzitza (separation from the body) for my tefillin?

Answer: The Rashba (Shut III:282) believes that the laws of chatzitza do not apply to the tefillin shel rosh. However, the accepted opinion is that chatzitzot are a problem, although possibly only for the bayit and not the retzuot (straps) (see Shulchan Aruch and Rama, Orach Chayim 27:4 and Mishna Berura 27:16).
Many poskim (including Igrot Moshe, OC IV:40.18; Aseh Lecha Rav III:3; Yalkut Yosef, OC 27:14) posit that a removable toupee is a chatzitza. However, Rav Moshe posits that transplanted hair is not a chatzitza since it is a permanent, desired part of his body. Furthermore, he writes that is also true for a permanently glued-on toupee. Is a toupee that is glued down for a matter of months a temporary or permanent appendage to the body?
Matters of chatzitza on appendages that remain for an extended period are discussed regarding items such as removable stitches and temporary fillings for women going to the mikveh. In that context, many poskim (see opinions in Badei Hashulchan 198:179 and The Laws of Nidda (Forst), vol. II, p.313-4) are lenient to allow tevilla. One of the lenient factors (see Igrot Moshe, YD I:97) is that the ostensible chatzitza is something that is specifically needed for medical reasons for a significant amount of time. This factor is missing in our case. However, several poskim are lenient in a case of aesthetic need to allow a married woman to have braces on her teeth (see The Laws of Nidda ibid.), and that is parallel to our case. Our case is also better than braces in that people want to remove the braces as soon as possible, whereas you would want to keep the toupee as long as you can.
There are various opinions regarding how long the item needs to remain on the body: six months; a month; a week (see ibid.). Finally, if, for example, the required time is a month, then according to some opinions, the appendage becomes a chatzitza a month before it will be removed; others say that if it is on for a month, it is okay until it is removed (see ibid.). Your situation is better if the toupee is being removed to be re-glued rather than replaced. A woman who wants to follow the stringent opinion can accordingly synchronize going to the mikveh and removing the appendage; a man who has to put on tefillin every day cannot.
Let us halachically contrast tevilla and tefillin. On the one hand, tevilla is needed to remove a more stringent halachic matter than tefillin. Also, we saw an opinion that chatzitza is not a problem for the tefillin shel rosh. Yet, in other ways, your case is more severe. A chatzitza on a minority of the body (as in the cases above) is no worse than a Rabbinic disqualification (Nidda 67b). In contrast, the entire area of the tefillin is covered by a toupee, and there is thus the potential for a Torah-level disqualification (see Ran to Rif, Sukka 13b). Some even argue that the parameters of chatzitza for tefillin are broader than for tevilla (see Rivevot Ephrayim III;38), and some claim that even one’s own hair that is under the tefillin in an unnatural way is a chatzitza (Machatzit Hashekel 27:4). A toupee should be no better than that.
In summary, it is likely that the toupee in question would not be a chatzitza (and one could make a beracha on the tefillin while it is on) as long as it is still considered desirable. However, we cannot deny that according to significant opinions, the mitzva of tefillin could be compromised. In the following way a removable toupee has an advantage. Several poskim allow one who will be embarrassed to remove it publicly to put on tefillin at home without the toupee, say Kri’at Shema, and then daven in shul with tefillin on the toupee without a beracha (Igrot Moshe ibid.; Aseh Lecha Rav, ibid.).