Returns CMS-published per-measure star-level cut points (the threshold a contract must reach for stars 2 to 5) for a rating_year, read through the Stars measure spine so a measure keeps its identity across years even when CMS renumbers its code (27 of 33 Part C codes moved for RY2026).

TWO SHAPES. Pass measure_id (that year's code, e.g. C09; a trailing ':' as stored is accepted) or measure_identity_key (the stable key, e.g. 'c:controlling_blood_pressure') for ONE measure: value.measure carries the identity, the star_2 to star_5 thresholds with their ops, the prior and next year's code and the ladder direction; value.cutpoints carries the raw CMS rows; include_history=true adds value.history, the same identity's ladder in every rated year (cut point drift). With neither, value.measures is a paged index of the year's measures (limit, offset; default 50 rows) and the answer names the per-measure call.

LADDER. CMS calculates MA-PD and PDP Part D cut points separately. The header (value.measure and the index rows) reads the ladder for org_subtype: MA-PD by default (the Medicare Advantage question), PDP for a stand-alone drug plan question; cutpoint_org_subtype names the ladder read, and it is ALL only where CMS published one ladder for every organisation (Part C). org_subtype (MA-PD | PDP | ALL) and star_level (1-5) also filter the raw rows.

Use cases: 'what is the 4-star line for Controlling Blood Pressure in RY2027?'; 'how did that line move since RY2024?'; 'how much would contract H1234 need to improve to reach 5 stars on D08?'.

SOURCE: CMS Tech Notes Attachment H (Tukey-aware threshold tables) for RY2024+, Attachment H pre-Tukey for RY2017-RY2023, pre-fixed cut points for RY2015-RY2016. RY2027 is CMS's final release (the 2027 Data Tables, 2026-10-08); the plan-preview rows it replaced stay readable as superseded (is_current = false). Spine: medicare_semantic.dim_stars_measure_identity_v6 (tools/ma_brain/stars_measure_spine_publish.py), whose direction flag agrees with CMS's own cut point ladder in every rated year.

HOLDINGS ARE NAMED, NEVER IMPLIED. When a rating year holds only ONE Part D ladder the answer says so and which population it is for. A measure with no cut point rows in a year is reported as not held in this edition, with the years held named; CMS publishes cut points every year. Thresholds are served at the precision CMS publishes (float32 storage noise is removed on the wire).