---
title: "NIST 800-171 3.1.8 (AC.L2-3.1.8): Unsuccessful Logons"
description: "NIST SP 800-171 3.1.8 Unsuccessful Logons: 1 SPRS point, allowed on a CMMC POA&M. The text, what assessors check and the evidence."
url: https://policycortex.com/nist-800-171/access-control/3.1.8
sealed: 2026-11-11
amended: 2026-11-11
register: nist-800-171/access-control/3.1.8
records: 7
digest: sha3:97b1c206ae70b9296e7b74bbcab777cd7801e0dcd353e63e8a4e12313bd28ba0
---

# NIST 800-171 3.1.8 (AC.L2-3.1.8): Unsuccessful Logons

NIST 800-171 / Access Control / 3.1.8

"Limit unsuccessful logon attempts." ([NIST SP 800-171 Rev. 2, requirement 3.1.8](https://doi.org/10.6028/NIST.SP.800-171r2))

CMMC Level 2 practice AC.L2-3.1.8.

## What 3.1.8 means in practice

Repeated wrong passwords should trigger a lockout or a growing delay, so passwords cannot be guessed at speed. Choose the threshold and the lockout period, write them down, and set them wherever people sign in: the identity provider, servers, network devices and applications with their own logins.

## SPRS points and the CMMC POA&M

- **CMMC Level 2 practice**: AC.L2-3.1.8
- **SPRS points**: 1 point. When it is not met, the DoD Assessment Methodology subtracts 1 from the score of 110.
- **CMMC POA&M**: Allowed. It is worth 1 point, and 32 CFR 170.21(a)(2)(ii) admits requirements worth 1 point. Conditional status also needs a score of at least 88, and the item must be closed within 180 days.

Sources: [NIST SP 800-171 DoD Assessment Methodology, version 1.2.1 (June 24, 2020), Annex A](https://www.acq.osd.mil/asda/dpc/cp/cyber/docs/safeguarding/NIST-SP-800-171-Assessment-Methodology-Version-1.2.1-6.24.2020.pdf); [32 CFR 170.21, Plan of Action and Milestones requirements](https://www.ecfr.gov/current/title-32/section-170.21).

## What an assessor checks for 3.1.8

NIST SP 800-171A gives 2 determination statements for 3.1.8, each found satisfied or other than satisfied. Determine if:

- 3.1.8[a] the means of limiting unsuccessful logon attempts is defined.
- 3.1.8[b] the defined means of limiting unsuccessful logon attempts is implemented.

[NIST SP 800-171A (June 2018), assessment objectives for 3.1.8](https://doi.org/10.6028/NIST.SP.800-171A)

## Evidence that shows 3.1.8 is met

- The documented lockout threshold and lockout duration.
- Identity provider lockout settings, such as Microsoft Entra smart lockout or an Okta password policy.
- Group Policy or device settings that apply the same limit on servers and workstations.
- Logs showing an account locked after repeated failures.

## How PolicyCortex gathers the evidence

PolicyCortex reads this evidence with the collectors below, read only, and grades 3.1.8 from it. Each line says what the product checks.

- **Microsoft Entra ID: Smart lockout.** Checks that Microsoft Entra smart lockout is configured to limit unsuccessful sign-in attempts.
- **Okta: Policies.** Checks that every active Okta password policy locks an account after at most 10 failed attempts, for at least 15 minutes.

## Related pages

- **Calculator**: [SPRS score calculator: mark 3.1.8 and the other 109 requirements and see the score.](https://policycortex.com/sprs-score-calculator#family-AC)
- **Sample package**: [Sample package: an SSP, a POA&M and an evidence chain the product generated from demonstration data.](https://policycortex.com/sample-package)
- **Family**: [All 22 Access Control requirements (3.1).](https://policycortex.com/nist-800-171/access-control)
- **Previous**: [3.1.7: Privileged Functions](https://policycortex.com/nist-800-171/access-control/3.1.7)
- **Next**: [3.1.9: System Use Notices](https://policycortex.com/nist-800-171/access-control/3.1.9)
- **All requirements**: [All 110 NIST SP 800-171 requirements, by family.](https://policycortex.com/nist-800-171)

Meet the requirement once. Keep the evidence current. [Request Access](https://app.policycortex.com/auth?mode=request-access) · [Book a call](https://policycortex.com/book)

## Register colophon

| Seq | Label | SHA3-256 | Prev |
|---|---|---|---|
| REC 0000 | REQUIREMENT | def4150796ab | d183094c79e1 |
| REC 0001 | MEANING | 72afa982036f | def4150796ab |
| REC 0002 | POINTS AND POA&M | 277a648fbf5b | 72afa982036f |
| REC 0003 | ASSESSMENT OBJECTIVES | 03f80e6d6fdb | 277a648fbf5b |
| REC 0004 | EVIDENCE | 7a6e42a4598e | 03f80e6d6fdb |
| REC 0005 | COLLECTORS | b06ee54be9bf | 7a6e42a4598e |
| REC 0006 | RELATED | 97b1c206ae70 | b06ee54be9bf |

Head sha3:97b1c206ae70b9296e7b74bbcab777cd7801e0dcd353e63e8a4e12313bd28ba0. Each digest is SHA3-256 over the previous digest, the register key, the record label, and the record copy; a second party can recompute it from this document.