Key points
- Michigan has three gross indecency statutes, covering acts between males, between females, and between a male and a female; each is a felony punishable by up to 5 years in prison or a fine of up to $2,500.[1]
- None of the statutes defines "gross indecency"; the model jury instruction lists the kinds of sexual acts that can qualify and says the list is not exhaustive.[2]
- The Court of Appeals has said that oral sexual conduct is not grossly indecent in and of itself; the question is whether it was performed where the unsuspecting public could be exposed to or view it.[3]
- The Michigan Supreme Court has held that procuring or attempting to procure an act of gross indecency with a person under the age of consent can support a conviction regardless of whether the conduct was in public.[4]
- Gross indecency is a registrable offense when committed against a minor: Tier II for a victim aged 13 to 17, with two consent-based exceptions, and Tier III for a victim under 13.[5][6]
Gross indecency is a Michigan felony set out in three statutes that date from the 1931 Penal Code and its 1939 additions and were last amended in 1952.[7][8] Each makes it a crime to commit, be a party to, or procure an "act of gross indecency," in public or in private, and each carries up to 5 years in prison or a fine of up to $2,500.[1] None of them says what gross indecency is. That has been left to the courts and to the model jury instructions.[2]
This page explains the three statutes, the penalty, how courts have defined the offense, the public place element, the rule for minors, and when registration applies.
The three statutes
| Statute | Who it applies to |
|---|---|
| MCL 750.338 | Any male person who commits or is a party to the commission of, or procures or attempts to procure the commission by any male person of, any act of gross indecency with another male person[7] |
| MCL 750.338a | Any female person who commits or is a party to the commission of, or any person who procures or attempts to procure the commission by any female person of, any act of gross indecency with another female person[7] |
| MCL 750.338b | A male person who commits or is a party to an act of gross indecency with a female person; a female person who does so with a male person; and any person who procures or attempts to procure such an act between a male person and a female person[8] |
All three contain the words "in public or in private."[7][8] The three sections differ in who they name; the prohibited "act of gross indecency" and the penalty are the same in each.[1]
Penalties
| Situation | Penalty stated in the statutes |
|---|---|
| Gross indecency | Felony; imprisonment for not more than 5 years, or a fine of not more than $2,500[1] |
| Person was a sexually delinquent person at the time of the offense | "May be punishable" by an indeterminate prison term, minimum 1 day and maximum life[7][1] |
The wording is "5 years, or by a fine," not "or both."[1]
The sexually delinquent person alternative
A "sexually delinquent person" is defined in MCL 750.10a as a person whose sexual behavior is characterized by repetitive or compulsive acts indicating a disregard of consequences or the recognized rights of others, by the use of force in attempting sex relations, or by sexual aggressions against children under 16.[9] Sexual delinquency is an alternate sentencing provision and not a separate crime, and the three gross indecency statutes are among the five offenses it attaches to.[10]
The charging document may also charge that the defendant was a sexually delinquent person at the time of the offense, and sexual delinquency must be proved beyond a reasonable doubt.[11] The gross indecency statutes use the permissive phrase "may be punishable" for the 1-day-to-life term.[7] In People v Arnold (2018), a case about the indecent exposure statute, the Michigan Supreme Court read the 1-day-to-life "alternate sentence" in the procedure statute that is common to these offenses as an option a sentencing judge could draw upon, alongside and not to the exclusion of other available options.[12] The Court's two Arnold opinions are explained in Indecent exposure.
What is an "act of gross indecency"?
Because the Legislature did not define the term, the working definition comes from two sources.
The model jury instruction
M Crim JI 20.31 lists the kinds of sexual act that can be charged. Its list includes masturbation of oneself or another, and masturbation in the presence of a minor, whether in a public place or private place.[2] The use note states that the list "is not intended to be exhaustive."[2] The instruction was revised in August 2025.[2]
Court decisions
- Sexual in nature. In People v Drake, the Court of Appeals said the operative principle is that the activity be sexual in nature, and that behavior can qualify even if it does not involve the specific acts usually charged.[13]
- Overt. The same decision says the acts must be overt in the sense that they are open and perceivable, and that the motivation for the behavior can be inferred from the totality of the circumstances and should be considered case by case.[13]
- No assault needed. The Court of Appeals has said gross indecency "does not require an assault, and may even occur between consenting participants."[14]
Criminal sexual conduct is a separate group of offenses with different elements. See Michigan criminal sexual conduct law.
The public place element
Although the statutes say "in public or in private," the model instruction requires the jury to find that the sexual act was committed in a public place, unless the only theory charged is masturbation in the presence of a minor.[2]
The instruction defines the term: "A place is public when a member of the public, who is in a place the public is generally invited or allowed to be, could have been exposed to or viewed the act."[2]
That language comes from the case law. In People v Brown, the Court of Appeals said that the sexual conduct at issue was not grossly indecent in and of itself; it was the act performed in a public place that violated the statute. The key issue, the court said, "is not so much the exact location of the act, but whether there is the possibility that the unsuspecting public could be exposed to or view the act."[3]
The Court of Appeals used the same reasoning for a married couple: in People v Jones, it said the conduct alleged, in a public visiting room in the presence of others, would constitute an act of gross indecency under MCL 750.338b.[14]
When a minor is involved
The public place analysis does not apply in the same way when the conduct involves a person under the age of consent. In People v Lino, the Michigan Supreme Court held that procuring or attempting to procure an act of gross indecency with a person under the age of consent can support a conviction "regardless of whether the conduct is performed in public."[4] The Court said the defendant in that case was on notice that sexual activity involving persons under the age of consent could constitute gross indecency.[15]
The model instruction reflects this by listing masturbation in the presence of a minor as an act that qualifies "whether in a public place or private place."[2]
Sexual conduct with a minor is also addressed by the criminal sexual conduct statutes, the accosting statute and the child sexually abusive activity statute, each with its own elements. See Age of consent in Michigan, Statutory rape laws and Accosting or soliciting a child.
"Procures or attempts to procure"
Each statute reaches a person who "procures or attempts to procure" an act of gross indecency.[7][8] In People v Masten, the Michigan Supreme Court read that language as aimed at a person who facilitates or attempts to facilitate an act by two other persons. The Court described the statute as proscribing two kinds of conduct: committing gross indecency and bringing about gross indecency.[16] A defendant may not be convicted of attempting to procure an act that would be between the defendant and another person.[16]
Constitutional questions
In People v Lino, the Michigan Supreme Court rejected vagueness challenges to MCL 750.338 as applied to the conduct in the cases before it.[15]
In Lawrence v Texas (2003), the U.S. Supreme Court held that a Texas statute making it a crime for two persons of the same sex to engage in certain intimate sexual conduct violated the Due Process Clause, in a case about adults engaging in private conduct.[17] No Michigan decision reviewed for this guide states how Lawrence affects the "in private" wording of the gross indecency statutes, so this page does not state a rule on that point. The related question for Michigan's sodomy statute is discussed in Sodomy law status.
Sex offender registration
| Circumstances | Registry treatment in the statute |
|---|---|
| Committed against an individual under 13 | Tier III[6] |
| Committed against an individual 13 or older but under 18 | Tier II, unless the court determines a consent-based exception applies[5] |
| Person was a sexually delinquent person at the time of the offense | Tier I[18] |
| Other cases | Not named on the tier lists by section number[19] |
The two exceptions to Tier II are that the victim consented, was at least 13 but less than 16, and the individual is not more than 4 years older; or that the victim consented, was 16 or 17, and was not under the individual's custodial authority.[5] A Tier I offender must comply with the registration act for 15 years, a Tier II offender for 25 years, and a Tier III offender for life.[20]
See SORA tiers and Michigan's "Romeo and Juliet" provisions.
Related offenses and time limits
- Indecent exposure. Knowingly making an open or indecent exposure is a misdemeanor punishable by up to 1 year, or up to 2 years if the person was fondling a part of his or her body listed in the statute during the exposure.[21][22]
- Indecent or obscene conduct in a public place. This is a disorderly person offense, a misdemeanor punishable by up to 90 days, a fine of up to $500, or both.[23]
- Open and gross lewdness. A misdemeanor punishable by up to 1 year or a fine of up to $1,000, with its own 1-year time limit for prosecution.[24]
- Prostitution-related offenses. These are covered in Prostitution and solicitation laws.
For offenses with no period of their own in the limitations statute, charges may be filed within 6 years after the offense.[25] See Statute of limitations for sex crimes.
What people get wrong
"Gross indecency only applies to gay sex." There are three statutes covering every combination of participants, and the Court of Appeals has said the male-female statute can reach a married couple's conduct in a public place.[1][14]
"Any act of oral sex is gross indecency." The Court of Appeals has said that oral sexual conduct is not grossly indecent in and of itself; performing it in a public place is what brings it within the statute.[3]
"It has to involve force." Gross indecency does not require an assault and may occur between consenting participants.[14]
"If it happened in private, it can never be charged." The Supreme Court has held that procuring or attempting to procure an act of gross indecency with a person under the age of consent can support a conviction regardless of whether the conduct was in public.[4]
"The statute lists what is prohibited." It does not; the model instruction's list is expressly non-exhaustive.[2]
Common questions
What counts as gross indecency in Michigan?
The statutes do not define it. The model jury instruction lists sexual acts that can qualify, including masturbation of oneself or another and masturbation in the presence of a minor, and its use note says the list is not intended to be exhaustive.[2] The Court of Appeals has said the operative principle is that the activity be sexual in nature and that the acts be overt, meaning open and perceivable.[13]
Does gross indecency apply to private consensual acts between adults?
The statutes say "in public or in private."[7][8] The model jury instruction, however, tells the jury it must find the act was committed in a public place unless only the minor-presence alternative is charged.[2] The Court of Appeals has said that oral sexual conduct is not grossly indecent in and of itself; what violates the statute is performing it in a public place.[3]
Is gross indecency a felony?
Yes. Each of the three statutes makes it a felony punishable by imprisonment for not more than 5 years, or by a fine of not more than $2,500.[1] If the person was a sexually delinquent person at the time, the offense "may be punishable" by an indeterminate term of 1 day to life.[7]
Do the gross indecency laws only apply to same-sex conduct?
No. MCL 750.338 covers acts between males, MCL 750.338a covers acts between females, and MCL 750.338b covers acts between a male and a female.[1] In People v Jones, the Court of Appeals said that the conduct alleged against a married couple in a public visiting room would constitute an act of gross indecency under MCL 750.338b.[14]
Does a gross indecency conviction require sex offender registration?
It depends on the age of the other person. A violation committed against an individual aged 13 to 17 is a Tier II offense unless the court finds one of two consent-based exceptions applies, and a violation committed against an individual under 13 is a Tier III offense.[5][6] The tier lists do not otherwise name these sections, apart from the separate Tier I entry for offenses by a sexually delinquent person.[19][18]
What does "procures or attempts to procure" mean?
The Michigan Supreme Court said in People v Masten that this language applies where the defendant facilitates or attempts to facilitate an act of gross indecency by two other persons. A person may not be convicted of attempting to procure an act that would be between the defendant and another person.[16]
Sources
- MCL 750.338; MCL 750.338a; MCL 750.338b — Michigan Legislature
- M Crim JI 20.31 — Michigan Courts
- People v Brown, 222 Mich App 586, 591-592 (1997) — Michigan Courts
- People v Lino, 447 Mich 567, 578 (1994) — Michigan Courts
- MCL 28.722(t)(v), (vi) — Michigan Legislature
- MCL 28.722(t)(i)–(iv), (viii), (ix); MCL 28.722(v)(i)–(iii) — Michigan Legislature
- MCL 750.338; MCL 750.338a — Michigan Legislature
- MCL 750.338b — Michigan Legislature
- MCL 750.10a — Michigan Legislature
- People v Arnold, 502 Mich 438, 464-465 (2018); People v Craig, 488 Mich 861 (2010) — Michigan Courts
- MCL 767.61a; People v Helzer, 404 Mich 410, 417, 424-426 (1978) — Michigan Legislature
- People v Arnold, 502 Mich 438, 444, 464-465, 469, 471, 482 (2018) — Michigan Courts
- People v Drake, 246 Mich App 637, 642 (2001) — Michigan Courts
- People v Hack, 219 Mich App 299, 307-308 (1996); People v Jones, 222 Mich App 595, 597, 604 (1997) — Michigan Courts
- People v Lino, 447 Mich 567, 575-578 (1994); MCL 28.722(t)(vi), (v)(i) — Michigan Courts
- People v Masten, 414 Mich 16, 17, 19 (1982) — Michigan Courts
- Lawrence v Texas, 539 US 558 (2003) — Legal Information Institute, Cornell Law School
- MCL 28.722(r)(i), (ii), (vi), (viii), (ix) — Michigan Legislature
- MCL 28.722(r), (t), (v) — Michigan Legislature
- MCL 28.725(11)–(13) — Michigan Legislature
- MCL 750.335a(2)(a) — Michigan Legislature
- MCL 750.335a(2)(b) — Michigan Legislature
- MCL 750.167(1)(c), (f); MCL 750.168(1) — Michigan Legislature
- MCL 750.335; 2023 PA 78 — Michigan Legislature
- MCL 767.24(10)-(11) — Michigan Legislature
This page is general legal information about Michigan law, published by the office of Attorney Shawn Haff. It is not legal advice and reading it does not create an attorney-client relationship. Laws change and every case turns on its own facts — check the sources linked above and talk to a licensed Michigan attorney about your situation. If you are in danger, call 911. The National Sexual Assault Hotline is 1-800-656-4673.