Assessment data can be collected over a period of the first 5 days of SOC or 2 days for ROC per CMS, individual agencies may shorten that time frame, most likely for billing reasons for Medicare patients so that the initial partial payment can be received as soon as possible.
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Page 62 Q19.1 Assessment data can be collected in collaboration with other disciplines' assessments performed in the 1st 5 days of SOC.
If insufficient data was collected in the first visit then data collected on a subsequent visit within 1st 5 days can be used to complete the SOC oasis. A good example would be nutritional and functional information not collected first day due to the time required to perform CVR and wound assessments, complete PICC care and infusion teaching and the patient becomes too exhausted at that point to complete the comprehensive assessment that can wait until a subsequent visit (as well as obtaining functional assessment data in collaboration with the therapy evals).
In the case of the RN that made the SOC visit not being available to complete the paperwork, I would make a visit to collect remaining data and co sign the oasis, in addition to completing a routine visit note. Like Calliotter stated above, an agency isn't likely to have a specific policy to cover that uncommon instance.