Published April 22, 2019
Updated Updated December 16, 2019
Some circumcision opponents in the United States assert that there are no laws prohibiting circumcision and that legally anyone can perform the procedure. They point out that Jewish religious circumcision specialists - known as a mohels or mohelim - are allowed to operate without a medical license. One intactivist claimed that it would be perfectly legal if a six year-old girl circumcised her baby brother.
Ron Low, owner of a foreskin restoration company, recently wrote that "California law explicitly allows amateur home circumcision, and bars cities or counties from outlawing it."  Low is partly right and partly wrong.
It is not the case that anyone, even an untrained person, may perform a circumcision. In 2017 a Texas man pled guilty to felony injury to a child for using pruning shears to circumcise his girlfriend's 3 year-old son; he was sentenced to life in prison.  In 2018 a Missouri preacher was indicted for illegally circumcising two teenagers. "A grand jury indicted Curtis W. Abbott in August on two counts of child endangerment and one count of unauthorized practice of medicine or surgery - all of which are felonies." 
So why does the law allow certain people without a medical license to perform circumcision? A 2006 Washington state appeals court ruling is instructive. A father had attempted to circumcise his 8 year-old son at home. In his defense the father argued that religious circumcisions are allowed. The appeals court rejected the comparison, explaining that a mohel is not an untrained amateur:
¶26 ...although Baxter analogizes the act here to ritual circumcisions that have been performed for thousands of years and have never been held contrary to public policy, there are obvious distinctions. In the Hebrew faith, for example, ritual circumcisions are performed by mohels who are trained medical professionals or have at least been trained in the craft through apprentiship. Mohels must be qualified to perform the procedure and in some places are certified by hospitals. The law holds the mohel to "the professional standards of skill and care prevailing among those who perform circumcisions." The mohel uses special equipment, including a "finely honed blade of surgical steel" and a "non-restricting guard." And the ritual circumcision is performed at infancy, where the procedure is simpler. ¶27 By contrast, Baxter attempted to circumcise his eight-year-old son in a dirty bathtub, with no medical training, using a hunting knife and animal wound cauterizing powder as his tools. Even when performed by trained professionals, circumcision has been criticized by some for the pain it causes and its inherent risk of complications. Given these risks, performing a circumcision as Baxter did here violates public policy. 
[legal citations omitted, emphasis added]
A typical mohel may have significantly more experience performing neonatal circumcisions than a typical pediatrician. Longtime mohels have been considered experts on the procedure.
What about Ron Low's claim with respect to California law? Let's take a look at the state's legislative history.
In 2011 anti-circumcision activists circulated a petition to prohibit elective circumcision for all boys under 18 within the city of San Francisco.  Petition supporters gathered enough signatures to qualify the measure for the municipal ballot. However four months before the election, a judge removed the measure from the ballot, ruling that the measure violated an existing statute that precludes local jurisdictions from regulating medical procedures. 
In response to the ballot measure, Assemblyman Mike Gatto introduced AB-768, a bill to convert the existing policy into state law. Brendon Marotta, producer of the anti-circumcision documentary American Circumcision, claimed that pro-circumcision groups got the law passed.  In fact it was Gatto who created the bill - because "he wanted to prevent local governments from creating their own 'patchwork of regulations' covering medical procedures in the state."  The measure not only prohibited cities and counties from imposing local restrictions, it also declared that "male circumcision has a wide array of health and affiliative benefits."  The bill passed both houses of the legislature by unanimous vote. Governor Jerry Brown signed the bill into law two months after the San Francisco ballot measure was struck down. 
Low is correct that California law prevents cities and counties from banning circumcision. However he is not correct in claiming that state law allows untrained amateurs to perform the procedure. The law does not specify who may or may not perform the procedure. AB-768 simply states that "No [local entity] shall prohibit or restrict the practice of male circumcision, or the exercise of a parent’s authority to have a child circumcised."  It is likely that someone with no training who performed a circumcision in California would face charges similar to the cases in the other states.
 Ron Low; Facebook post; March 24, 2019; (Facebook.com/TLCTugger)
 "Life sentence for cutting boy's penis"; Daily Sun; December 25, 2017. The child received reconstructive surgery.
 Associated Press; "Nixa man, a failed polygamist and minister, accused of illegally circumcising 2 teens"; Springfield News-Leader; October 10, 2018. The charges were later dropped as part of a deferred prosecution agreement.
 "State v Baxter"; Court of Appeals of Washington, Division 2, No. 32766-0-II; Decided August 15, 2006; found at FindLaw
 Note the irony that intactivists - who recite the mantra "HIS body, HIS choice" - would prohibit 16 and 17 year-old boys from choosing circumcision.
 Mikaela Conley; Proposed Circumcision Ban Struck From San Francisco Ballot"; ABC News; July 28, 2011
 Brendon Marotta; Facebook post; April 2, 2019 (Facebook.com/bdmarotta)
 Benny Evangelista, "Circumcision law blocks local bans"; San Francisco Chronicle; October 3, 2011
 Assembly Bill No. 768 Male circumcision (2011-2012); California Legislative Information; Filed with Secretary of State October 2, 2011
 Christopher Yee; "Brown signs bill banning anti-circumcision laws in California"; The Daily Californian; October 3, 2011