The market taxonomy of biosimilars by type delineates the product portfolio into molecular classes that determine manufacturing complexity, regulatory pathways, and revenue potential. Monoclonal antibody (mAb) biosimilars dominate, representing roughly 55 % of global sales, because they substitute high‑price originators across oncology and autoimmune indications; sub‑categories such as anti‑TNF (e.g., adalimumab) and anti‑VEGF (e.g., bevacizumab) each capture significant market slices. Fusion‑protein biosimilars, accounting for about 15 % of sales, include agents like etanercept and abatacept, where the protein‑protein linkage adds production challenges but also creates cost‑saving opportunities. Hormone biosimilars, notably insulin analogs and growth‑hormone variants, contribute roughly 20 % of the market, driven by chronic disease prevalence and volume‑based reimbursement models. Enzyme biosimilars, such as recombinant erythropoietin and filgrastim, hold near 8 % of revenue, reflecting steady demand in supportive care. The residual Other category (≈2 %) covers emerging formats like bispecific antibodies and cell‑derived therapeutics, indicating nascent growth avenues. Understanding this type‑based segmentation guides R&D allocation, supply‑chain design, and competitive positioning across the biosimilars treatment landscape.