The agency made the change via a notice rather than a rulemaking on Wednesday, and will not accept comments on the decision. The CMS said rulemaking was unnecessary because the updates don’t reflect any “substantive” changes in policy.

Medicare payments to inpatient psychiatric facilities were estimated to be $4.4 billion in 2014, according the most recent federal data available. That’s up slightly from $3.9 billion in 2008.

On average, Medicare beneficiaries account for about one-fourth of psychiatric facilities’ discharges. In 2014, 292,000 beneficiaries had about 437,000 Medicare discharges from IPFs. Those numbers differ slightly from 295,000 beneficiaries who accounted for almost 443,000 stays in 2008. About 1,563 facilities submitted Medicare cost reports in 2014.

The facilities may be seeing an increase in Medicaid payments after the CMS lifted a 50-year ban on mental health institutions receiving the funds last year.

Since the creation of Medicaid in 1965, the program excluded payment for institutions of mental disease (IMDs) for beneficiaries 21 and over. Most residential treatment facilities for mental health and substance-use disorders with more than 16 beds did not qualify for Medicaid reimbursement.

Decades ago, states were responsible for the care of people with severe mental illness.

Last spring, the CMS finalized a policy allowing Medicaid managed-care plans to pay the facilities for stays lasting 15 or fewer days in a month.