42 CFR §488.730

1. (a)Basic period. Each HHA must be surveyed not later than 36 months after the last day of the previous standard survey. Additionally, a survey may be conducted as frequently as necessary to—
   1. (1)Assure the delivery of quality home health services by determining whether an HHA complies with the Act and conditions of participation; and
   2. (2)Confirm that the HHA has corrected deficiencies that were previously cited.
2. (b)Change in HHA information. A standard survey or an abbreviated standard survey may be conducted within 2 months of a change, or knowledge of a change, in any of the following:
   1. (1)Ownership;
   2. (2)Administration; or,
   3. (3)Management of the HHA.
3. (c)Complaints. A standard survey, or abbreviated standard survey—
   1. (1)Must be conducted of an HHA within 2 months of when a significant number of complaints against the HHA are reported to CMS, the State, the State or local agency responsible for maintaining a toll-free hotline and investigative unit, or any other appropriate Federal, State, or local agency; or
   2. (2)As otherwise required to determine compliance with the conditions of participation such as the investigation of a complaint.