Standards of care for gender identity disorders
In many countries or areas, an individual's pursuit of hormone replacement therapy (HRT) and/or sex reassignment surgery (SRS) is often governed, or at least guided, by documents called standards of care (SOC), or standards of care for gender identity disorders.  Various medical and psychiatric fields have developed similar protocols for treatments, covering topics ranging from diabetes patients to sexual abuse victims.
Prior to the advent of the first SOCs, there was no semblance of consensus on psychiatric, psychological, medical, and surgical requirements or procedures.  Before the 1960s, few countries offered safe, legal medical options and many criminalized cross-gender behaviors or mandated unproven psychiatric treatments.  In response to this problem, the Harry Benjamin International Gender Dysphoria Association (HBIGDA) authored one of the earliest sets of clinical guidelines for the express purpose of ensuring "lasting personal comfort with the gendered self in order to maximize overall psychological well-being and self-fulfillment." These standards are still the most well known, however, other sets of SOCs, protocols and guidelines do exist, especially outside the USA.

# HBIGDA standard of care
The Standards of Care for Gender Identity Disorders by the Harry Benjamin International Gender Dysphoria Association (HBIGDA-SOC) are the most widespread SOC used by professionals working with transsexual, transgender, or gender variant people. The HBIGDA-SOC are periodically updated and revised as new scientific information becomes available. The latest revision was released February 20 2001. This is the sixth version of the HBIGDA-SOC since the original 1979 document was drafted. Previous revisions were released in 1980, 1981, 1990, and 1998.
Included in the guidelines are sections on epidemiology, mental health professionals, treatment of children, adolescents and adults, hormone replacement therapy, the Real-Life Experience (RLE), which was formerly called the Real-Life Test, and surgery.

# Summary of HBIGDA
The current revision mandates that mental health professionals document a patient's relevant history in a letter, which should be required by medical professionals prior to physical intervention. One letter is required for hormone replacement therapy or either augmentation mammoplasty or male chest reconstruction. Two additional letters are needed for genital surgeries.
The Eligibility Criteria and Readiness Criteria give certain very specific minimum requirements as prerequisites to HRT or SRS. For this and other reasons, the HBIGDA-SOC is a highly controversial and often maligned document among patients seeking medical intervention (hormones, and/or surgery), who claim that their legally protected right to proper medical care and treatment is unjustly and unduly withheld or even denied based on the SOC.
HBIGDA-SOC sections One through Four are introductory in nature, explaining (section I) the purpose, intent, and need for the SOC, (section II) epidemiological considerations relating to transsexual people, (section III) diagnostic nomenclature, and (section IV) the job of the mental health professional.
Sections Five through Eight begin the actual guide to treatment. Specifically the manner in which to diagnose transexualism in both minors and adults, the manner in which to document the diagnoses and recommendations ("The Letter") and also covers requirements and treatment using hormones, including use and effects of hormones.
Section Nine covers "The Real Life Experience" formerly the "Real Life Test".
HBIGDA-SOC sections Ten through Twelve specifically cover the surgical treatment of transsexual people. Section Twelve, titled "Genital Surgery," deals directly with all concerns about sex reassignment surgery. It includes six "Eligibility Criteria" and two "Readiness Criteria", which are intended to be used by professionals for both diagnosis and guidance before providing patients "letters of recommendation."
The Thirteenth and final section covers "post-transition follow-up".

# Criticism of the HBIGDA-SOC
Numerous criticisms have been made against the HBIGDA-SOC over the course of its history, some of which are reflected in later versions of the guidelines.  Most of these criticisms are related to the strictness of the requirements, noting that the rate of post-surgical regret among transsexual people is very low  lower than many medically-necessary and cosmetic procedures with less stringent requirements. Provisions related to the necessity of real-life experience (noting that requiring real-life experience in an incongruous anatomical/social role can be both mentally harmful as well as physically dangerous to the individual) have been particularly under fire as is the SOC's very strict requirements on the treatment of minors.  Under all but the most recent version of HBIGDA-SOC, even hormonal treatment to delay the onset of puberty was forbidden in all cases, leading to often irreversible bodily changes.  This has been changed to allow for hormone treatment (both hormone blockers and hormones) in limited circumstances.  The HBIGDA has also removed the set length of time for psychotherapy.
A criticism levied against surgeons who perform SRS deals with the rare non-SOC practice requiring patients to divorce their spouse before the surgery is performed.

# Other SOCs, protocols and guidelines for treatment of GID
In some countries or areas, local standards of care exist, such as in the Netherlands, Germany or Italy. Also, some health care providers have their own set of SOCs which have to be followed to have access to health care.
The criticism about the HBIGDA-SOCs applies to these as well; some of these SOCs are based on much older versions of the HBIGDA-SOCs, or are entirely independent of them. A more lenient version that has been increasing in acceptance is the Health Law Standards Of Care, developed by the Health Law Project (also known as the ICTLEP guidelines), which is based on a harm-reduction model.
Treatment according to such older SOCs is often reserved for transsexual people only, not for other transgender people who for example might not want to undergo the complete set of treatments, or who see themselves outside a binary gender system. Such older SOCs are often used to withhold medical interventions from transgender people altogether.
A dramatic elevation in surgical and post-surgical risks as well as an increased possibility of post-surgical dissatisfaction is often the exchange for lower costs and fewer pre-surgical requirements such as weight limits. In other regions, notably Latin America, surgeons follow no particular set standards and use their own criteria for eligibility for surgery.
In Western countries the emphasis is on psychiatry or psychology, typically in Latin America the emphasis is on the ability to "pass" and in Thailand the emphasis is on cross-living experience.
See also: List of transgender-related topics