Context-Conditioned Masked LoRA: Dynamic Rank Routing for Compute-Efficient Parameter-Efficient Fine-Tuning

Rifat Rafiuddin, Rafae Abdullah


Abstract
Parameter-efficient fine-tuning methods such as LoRA reduce trainable parameters, but still apply dense low-rank updates per token, leaving adaptation compute largely fixed once rank is set. We propose Context-Conditioned Masked LoRA (CCM-LoRA), which learns a lightweight router that activates an input-dependent subset of LoRA rank directions, turning LoRA into dynamic rank routing and enabling contextual sparsity in fine-tuning and inference. CCM-LoRA is trained with a budget-constrained objective that targets an expected effective rank (or FLOPs) while regularizing routing to avoid degenerate always-on/off masks. Across public NLU and multilingual benchmarks, CCM-LoRA improves the accuracy–efficiency Pareto frontier versus static-rank LoRA and adaptive-rank baselines, matching or improving task performance at lower inference-time effective rank. We also provide a reproducible profiling protocol and analyses of rank usage, router overhead, and robustness under domain and language shift.
Anthology ID:
2026.findings-acl.1329
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
Findings
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Publisher:
Association for Computational Linguistics
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Pages:
26670–26689
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URL:
https://preview.aclanthology.org/ingest-acl/2026.findings-acl.1329/
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Cite (ACL):
Rifat Rafiuddin and Rafae Abdullah. 2026. Context-Conditioned Masked LoRA: Dynamic Rank Routing for Compute-Efficient Parameter-Efficient Fine-Tuning. In Findings of the Association for Computational Linguistics: ACL 2026, pages 26670–26689, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Context-Conditioned Masked LoRA: Dynamic Rank Routing for Compute-Efficient Parameter-Efficient Fine-Tuning (Rafiuddin & Abdullah, Findings 2026)
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