US · guidance
CMS Pub. 100-02, ch. 4, § 10
Inpatient Psychiatric Benefit Days Reduction
A3-3104, HO-217
If an individual is in a participating psychiatric hospital on the first day of the entitlement
to hospital insurance, the number of inpatient benefit days in the first benefit period is
subject to reduction. The days (not necessarily consecutive) on which an individual was
an inpatient of a psychiatric hospital in the 150-day period immediately before the first
day of entitlement must be subtracted from the 150 days of inpatient hospital services for
which he/she would otherwise be eligible in the first benefit period. Days spent in a
general hospital for diagnosis or treatment of a psychiatric condition prior to entitlement
will not reduce the patient's 150 inpatient benefit days in the initial benefit period.
After entitlement, the reduction applies not only to inpatient hospital services received in
a psychiatric hospital, but also to services received in a general hospital if the individual
is an inpatient of the general hospital primarily for the diagnosis or treatment of mental
illness. If a patient has no psychiatric benefit days remaining because of the reduction,
Medicare payment may still be made for up to 150 days of inpatient hospital services that
are not for the diagnosis and treatment of mental illness.
EXAMPLE l:
John was admitted to a Medicare participating psychiatric hospital named Spring
Psychiatric Hospital on January 20. John’s Medicare entitlement was effective February
1 while John was still an inpatient of Spring Psychiatric Hospital. The 12 days of
inpatient psychiatric care prior to entitlement are deducted from the 150 days available in
the first benefit period. John has 138 days available in the first benefit period (150 minus
12 = 138).
EXAMPLE 2:
Mary was admitted to Spring Psychiatric Hospital on January 2 and discharged January
31. She was readmitted March 1 and discharged April 15. Mary’s Medicare entitlement
became effective April 1. Mary used a total of 60 psychiatric days in the 150 day period
prior to her Medicare entitlement. Therefore, the days available to Mary in her first
benefit period are 90 days. Pre-entitlement days used by Mary were 29 for her January
admission and 31 used during her March admission prior to her entitlement April 1.
History
(Rev. 1, 10-01-03)
Provenance
- Source
- cms.gov
- Retrieved
- 2026-08-25
- Edition
- iom-2026-08-25
- Content hash
36030e63800c559640639cef42c4a2f5565964af5c4787bc2f6d82f807ab326e
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