C0500 — Brief Interview for Mental Status (BIMS) — Summary Score
Response options, how to score it, and the error that most often sends the record back. Cited to Ch. 3, Item C0500.
Response options
| Value | Meaning |
|---|---|
| 00-07 | Severely impaired (scores 0–7) |
| 08-12 | Moderately impaired (scores 8–12) |
| 13-15 | Cognitively intact (scores 13–15) |
| 99 | Unable to complete interview |
How to score it
The BIMS is a standardized 3-part interview: temporal orientation (3 items, max 4 pts), ability to recall (3 words, max 3 pts), and orientation (day of week and current year, max 3 pts — but administered only if temporal orientation is attempted). Score is the sum of all sub-items (0–15 range). Score 99 if the interview could not be completed. See Guidance Manual Ch. 3, Section C for the full administration protocol.
The common error
Skipping the BIMS and defaulting to '99' without attempting the interview. Also: summing incorrectly across the three sub-sections. The BIMS must be conducted if A1255 = 1 (patient able to complete interview).
Source: OASIS-E2 Guidance Manual — Ch. 3, Item C0500. Verified 2026-04-26.
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