Lichenicolous fungi comprise a diverse group of highly specialized organisms inhabiting lichens, occurring as parasites, commensals or saprotrophs, either host-specific or generalists. Since our 2018 checklist, the field has seen remarkable growth, notably through the publication of the first two volumes of the Flora of Lichenicolous Fungi (2022, 2024), which described numerous new species and genera of Basidiomycota and hyphomycetes. Here, we present an updated classification and checklist of lichenicolous fungi in the Ascomycota and Basidiomycota, incorporating all relevant literature from 2018–2025. The checklist now includes 2,795 taxa (2,442 obligately lichenicolous [non-lichenized], 280 lichenized [including species that are facultatively or obligately lichenicolous, as well as juvenile forms initially growing on lichens before becoming independent], and 73 facultatively or doubtfully lichenicolous [non-lichenized] taxa), distributed among 454 genera, 125 families, 52 orders, and 15 classes—a substantial increase from 2,319 taxa in 2018. This edition reflects recent advances in taxonomy and phylogeny, with no new nomenclatural or taxonomic novelties proposed herein. Our work provides an authoritative and up-to-date reference for the global diversity and classification of lichenicolous fungi. Keywords: Lichenicolous lichens, microbiome, mycoparasites, phylogeny.