Medicaid · 42 U.S.C. §1396d · in force since 1965
Medicaid has refused to pay for adults in psychiatric institutions since it was created in 1965, and since 1988 the statute has drawn that line at 16 beds. If an adult between 21 and 64 is treated in a psychiatric or addiction facility with more than 16 beds, federal Medicaid pays nothing toward their care.
The average psychiatric hospital in the United States has 108 beds. So the rule does not fund small hospitals. It defunds almost all of them.
Federal bed limit
16
Unchanged since it entered the statute in 1988.
Average psychiatric hospital
108
Smaller than the average general hospital.
Hospitals under the limit
<8%
The rest cannot bill Medicaid for adult care.
State psychiatric beds
36,150
Down from 558,922 in 1955. A record low, in 2023.
State psychiatric hospital beds against the number of people held in state and federal prisons and in local jails, 1955 to the present. Points are census and survey years, and the line between them is a connector, not measured data. The series stop where the published figures stop: beds and prisons at 2023, jails at 2024. Everything to the right of that line is time we have no national count for yet, not a decline to zero.
Both axes use a square-root scale so a collapse from 559,000 and a rise past 1.6 million stay readable in one frame. Point values are shown on hover and tap.
These two lines are not a causal claim. Incarceration in the United States rose for many reasons — sentencing law, drug policy, and policing changed enormously over the same period. What the chart shows is that the country reduced its psychiatric hospital capacity to almost nothing and expanded its correctional capacity enormously, and that a federal funding rule adopted in 1965 made the first of those two things cheaper for states to do.
Two BJS measures are stitched here. Figures through 1980 count sentenced prisoners in state and federal institutions; from 1990 they count prisoners under the jurisdiction of state and federal authorities. Local jails are a separate line and are not added into the prison figure.
Medicaid pays for almost every kind of medical care. There is one category of facility it will not pay for, and psychiatric hospitals are it.
a hospital, nursing facility, or other institution of more than 16 beds, that is primarily engaged in providing diagnosis, treatment, or care of persons with mental diseases, including medical attention, nursing care, and related services42 U.S.C. §1396d(i) — Social Security Act §1905(i)
That is the definition of an institution for mental diseases, or IMD. The exclusion itself is a second passage, which says Medicaid will not pay for
any such payments with respect to care or services for any individual who has not attained 65 years of age and who is a patient in an institution for mental diseases42 U.S.C. §1396d(a), concluding paragraph, clause (B)
If you are between 21 and 64, and you are a patient in a psychiatric or addiction treatment facility with more than 16 beds, Medicaid will not pay for your care. Not the psychiatric care, and not the ordinary medical care either. The bar follows you: it also covers treatment delivered outside the facility while you are a patient there. If you are 65 or older, or under 21, separate exceptions apply.
A note on citations. The exclusion sits in the flush language after the §1905(a) service list. That list now runs to paragraph (32), so older citations such as §1905(a)(30)(B) reflect earlier numbering. We link the current United States Code text so you can read it yourself: 42 U.S.C. §1396d.
This is the question everyone asks. Here is everything that is documented.
None of the standard references explains why the number is 16 rather than 20, 30, or 50. There is no published cost model, bed-supply study, or clinical standard behind the figure in the sources checked here. It has not moved in the 38 years since, while the average psychiatric hospital has settled at 108 beds.
Sources checked for a rationale: CRS IF10222; MACPAC; Manhattan Institute (2021 and 2025); Legal Action Center; American Psychiatric Association; National Association of Medicaid Directors; Mental Health America.
If you find a published rationale for the figure, we want it. Send it to hello@16bedlimit.com and this section will be corrected with the citation.
The number was meant to favor small community settings over large institutions. The effect is that nearly every psychiatric hospital in the country falls on the wrong side of it.
Every psychiatric hospital larger than 16 beds is an institution for mental diseases, and Medicaid will not pay for adult care inside it. These are the measured landmarks of the national bed-size distribution.
Landmarks only. We do not have the full facility-by-facility distribution, so this is not drawn as a histogram. Source: Manhattan Institute, "U.S. Psychiatric Hospitals Under Medicaid's IMD Exclusion" (Aug 2025).
Because the rule is hard to live with, states ask the federal government for permission to ignore parts of it. That permission is a section 1115 demonstration waiver, and it is temporary, conditional, and narrower than it sounds.
States can ask CMS for a section 1115 demonstration waiver to bill Medicaid for short IMD stays anyway. Most have one for addiction treatment. Far fewer have one for mental health. Every square is one state, sized equally.
A waiver is a time-limited demonstration, not a change in the law. It usually covers only short stays and comes with CMS milestones the state has to hit.
Status as of 2025-01-14, from CRS IF10222, Table 1 (source: KFF Medicaid Waiver Tracker, Jan 14 2025). Waiver status changes; check the KFF tracker for the current picture. Separately, managed care plans may pay for stays of up to 15 days in a month, and a state plan option allows up to 30 days a year for substance use disorder treatment.
Congress has amended around this rule repeatedly. It has never removed it.
President Franklin Pierce vetoes federal land-grant funding for public mental institutions, reaffirming that paying for psychiatric care is a state responsibility. That premise is the ancestor of the IMD exclusion.
Manhattan Institute →The Social Security Amendments of 1965 establish Medicaid and, from day one, bar federal matching funds for adults in institutions for mental diseases. The stated intent was to stop states shifting the cost of their asylums onto the federal government. An exception for people 65 and older is included from the start.
CRS IF10222 →Congress creates an optional benefit letting states cover inpatient psychiatric services for people under 21. Because an EPSDT screen can find the care medically necessary, every state now covers it.
CRS IF10222 →The Medicare Catastrophic Coverage Act writes the IMD definition into law and adds the piece that had not been there before: facilities of 16 beds or fewer are exempt. Congress meant to favor small settings over large institutions. The number has not moved since.
CRS IF10222 →CMS tells states it will approve §1115 demonstration waivers covering short-term IMD stays for substance use disorder treatment. Updated November 2017.
CRS IF10222 →CMS regulation lets states pay managed care plans for enrollees aged 21-64 in an IMD as an "in lieu of" service, capped at 15 days in the payment month. The SUPPORT Act later writes this into statute.
MACPAC →Acting on a mandate in the 21st Century Cures Act, CMS issues guidance letting states seek §1115 waivers for short-term IMD stays for adults with serious mental illness and children with serious emotional disturbance.
CMS →§5052 adds a state plan option under SSA §1915(l) covering adults 21-64 with a substance use disorder in an eligible IMD for up to 30 days in a 12-month period. §1012 stops states denying federal match for non-IMD services delivered to pregnant and postpartum patients receiving SUD care in an IMD. §1013 codifies the 15-day managed care rule.
CRS IF10222 →The Michelle Alyssa Go Act would raise the threshold from 16 beds to 36. The Repealing the IMD Exclusion Act would strike the exclusion outright. Both are in committee.
CRS IF10222 →When a hospital bed is not available or not payable, the person in crisis still exists. They turn up somewhere, and the somewhere is usually an emergency department, a jail, or the street.
forensic
Of the state hospital beds still in service in 2016, close to half — roughly 5.5 of the 11.7 beds per 100,000 people — were occupied by forensic patients, meaning people charged with or convicted of a crime. By 2023 a majority of state hospital beds were forensic.
Treatment Advocacy Center →forensic
Forensic patients in state hospitals rose 76% between 1999 and 2014, from about 13,394 on a given day to more than 23,574 across 37 reporting states — while the total number of psychiatric beds kept falling.
Manhattan Institute (2025) →incarceration
Across 26 states, people in jail wait a median of 60 days for a bed to restore their competency to stand trial. At least 12 states have been sued for failing to provide that care in time.
Manhattan Institute (2025), citing Treatment Advocacy Center →incarceration
About 14% of people in state prison and 8% in federal prison met the threshold for serious psychological distress in the past 30 days — several times the rate in the general adult population.
Bureau of Justice Statistics, Survey of Prison Inmates 2016 →incarceration
Thirty-seven percent of people in prison and 44% of people in jail had previously been told by a mental health professional that they had a mental disorder.
Bureau of Justice Statistics, National Inmate Survey 2011-12 →homelessness
More than 770,000 people were experiencing homelessness on a single night in January 2024 — the highest count HUD has recorded. Serious mental illness is heavily overrepresented in this population.
HUD 2024 Annual Homelessness Assessment Report (Point-in-Time count) →emergency
Patients in psychiatric crisis wait up to three times as long as other patients to move from an emergency department to an inpatient bed. In San Francisco, 87% of people with 18 or more ED visits a year had a mental illness or substance use disorder.
Manhattan Institute (2025) →prevalence
Of non-elderly adult Medicaid enrollees have a serious mental illness.
Manhattan Institute (2025) →prevalence
Medicaid enrollees are 90% more likely to have a serious mental illness than privately insured Americans.
Manhattan Institute (2025) →Both are in the 119th Congress. Both are in committee. They disagree about whether to move the line or erase it.
Redefines an institution for mental diseases to exclude facilities of 36 beds or fewer, if they meet certain standards. Facilities up to 36 beds could bill Medicaid.
Status: Introduced; referred to committeeStrikes the exclusion from Title XIX entirely, so Medicaid could cover services for eligible patients in an IMD regardless of age, where the facility meets required care and staffing standards.
Status: Introduced; referred to committeeBill status is as retrieved on 2026-08-26. Follow the Congress.gov links for the current record, which is authoritative.
People who work on this in good faith disagree about whether the rule should go. Both cases are set out here as their proponents make them.
Every message goes to hello@16bedlimit.com. Each button below opens your email app with the subject and prompts already filled in.
Denial letters, state waiver correspondence, hospital transfer records, competency-restoration wait letters. Redact what you need to.
Compose emailWhich organizations, committees, and offices are actively moving on the IMD exclusion, and how to reach them.
Compose emailIf you or someone you care about could not get a bed, that is the evidence this argument runs on.
Compose emailFoundations, donors, and advocacy organizations — see the funding routes below.
Compose emailPeople often ask which vehicle is the right one for pushing on a federal funding rule. The honest answer is that it depends what you want to do, because each one permits different activity. This is a description of the rules, not legal advice.
| Vehicle | What it can do | What it cannot do | Authority |
|---|---|---|---|
| 501(c)(3) public charity | Research, public education, and a limited amount of direct lobbying. Donations are tax-deductible. | No campaign intervention for or against any candidate. Lobbying must stay within an insubstantial part of activities, or within the §501(h) expenditure limits if that election is made. | IRS — Lobbying by 501(c)(3) organizations |
| 501(c)(4) social welfare organization | Unlimited lobbying on the IMD exclusion as its primary activity, plus some political activity as a secondary purpose. | Donations are not tax-deductible. Political activity cannot be the primary activity. | IRS — Social welfare organizations |
| Super PAC (independent expenditure-only committee) | Raise and spend unlimited sums from individuals, corporations, and unions on independent expenditures supporting or opposing federal candidates. | May not contribute to, or coordinate with, a candidate or party committee. Must register and report to the FEC. | FEC — Independent expenditure-only committees |
| Registered lobbying | Direct advocacy to Members of Congress and their staff on H.R. 5462, H.R. 6727, or any successor. | Above statutory thresholds, registration and quarterly disclosure under the Lobbying Disclosure Act are mandatory. | Congress — Lobbying Disclosure Act filings |
Nothing on this page is estimated or recalled. Each figure was fetched from the source below on 2026-08-26. The same data is available as JSON at /api.
The question box on this page runs on these 14 sources and nothing else. It has no web access and is instructed not to answer from general knowledge, so if you ask it something these sources do not cover, it will tell you that instead of inventing an answer. Anything it tells you can be checked against the original, one link away.