This antwren occurs in eastern Amazonia. A 2025 systematics paper treats it as a full species distinct from the Myrmotherula menetriesii complex. Older field records under the former subspecies name describe solitary foraging in secondary-forest understory.
In the 1927 description of the former subspecies M. menetriesii omissa, males generally lacked a distinct black throat patch, while females were more ochraceous below.
A 1969 survey in the Acará River region recorded the former subspecies M. menetriesii omissa in secondary forest, foraging alone for arthropods among understory leaves.
An extinction-risk assessment has not been added yet.