Marriage: In the United States, don’t count on it. No state has affirmatively upheld the right of a post-operative transsexual to marry members of either sex, although New Jersey has come close. At least two states (Texas and Kansas) have held that post-operative transsexuals have no right to marry members of the sex opposite their current sex and have nullified such marriages on the request of third parties (in Texas, on the request of an insurance company representing an incompetent doctor, in Kansas by a disaffected heir).
Insurance: In general, if and when the post-operative transsexual obtains a legal “change of sex” order, the insurance company will give them the benefit of the lower rate (for male to female) or the disadvantage of the higher rate (for female to male). However, in some states, last I heard (Oregon and Ohio come to mind), legal orders for change of sex are not available. In most others an attestation from the surgeon is required (and this is also the procedure followed by the Social Security Administration). As to life expectancy, male-to-female transsexuals who have had surgery live longer than unaltered men (not surprising, as it’s well-known that eunuchs tend to outlive intact men) and in fact may (not clear statistically) outlive natural born women as well – if you factor out suicide, homicide, and sexually transmitted disease as causes of death. This may be in part because being successfully post-operative pretty much guarantees that you’re not poor, and income is one of the strongest predictors of lifespan in the United States today.
Driver’s license: In most states this follows the same rules as change-of-sex orders. However in some states (notably California) the license will reflect your appearance and not your genitals, on the highly reasonable theory that because the information on the license is supposed to assist with identification, a declaration of what you look like (which a police officer is likely to see) and not what you have between your legs (which a police officer is unlikely to see) is of greater value.
Pronouns: A post-transition transsexual should be referred to by the terms appropriate to the gender he or she presents himself or herself with. There is no clear answer as to what terms to use to refer to a post-transition transsexual’s life prior to transition. Do keep in mind that transsexuals are subject to a great deal of discrimination, and you should probably not talk about a transsexual’s pretransition life without talking to him or her about it first. There’s a good chance he or she would prefer that such discussions be avoided. This is also a good chance to get advice from the person in question.
Prior marriage: A sexual reassignment operation does not dissolve a marriage. “There is no surgery that can amputate a spouse.” Of course, sexual reassignment is grounds for divorce in those few states left that require grounds more detailed than “irreconcilable differences”.
The draft: Any individual who has transitioned from male to female is virtually assured of being found unfit to serve.
Birth certificates: Not all states will change the birth certificate. Some states do not list sex on the birth certificate. Some list sex but will change it. Some list sex, but refuse to change it. There is no consistency here.
Prison: Current law requires (federal court rulings) that transsexuals be housed with the population of their current physical sex. The law also requires that the prison continue any prescribed hormones that the individual may have been receiving prior to incarceration, but does not require that the prison fund any further procedures toward reassignment.
In general, the law treats transsexuals as though they were a member of whichever gender is least convenient to the transsexual at the present moment. For example, if a preoperative male-to-female transsexual enters a woman’s restroom, she runs a considerable risk of being arrested because she’s “male”. On the other hand, if she walks topless down the street, she runs a considerable risk of being arrested because she’s “female”. The law is less unfair for post-operative transsexuals, but there are still glaring inconsistencies.
Government should be gender-blind. There is no reason for legal distinctions between the sexes, except to the extent that there absolutely has to be a legal distinction because some people have wombs, and others do not. (Note that the government, and society in general, currently makes this distinction far more often than it needs to.)