OASIS · Section M
M0064 — Social Security Number
Response options, how to score it, and the error that most often sends the record back. Cited to Ch. 1, Item M0064.
Response options
| Value | Meaning |
|---|---|
| UK | Unknown or Not Available |
How to score it
Record the patient's 9-digit Social Security Number if known and available. If the patient declines to provide it or it cannot be verified, use code UK. SSN is an optional identifier — patients are not required to disclose it for home health services.
The common error
Pressuring the patient for an SSN they decline to share. Use code UK when the SSN is not available; M0064 is not a billing-required field, and demanding it can violate patient rights.
Source: OASIS-E2 Guidance Manual — Ch. 1, Item M0064. Verified 2026-04-26.
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