MS-DRG v44.0 · MDC 02: Diseases and Disorders of the Eye
121 — Acute Major Eye Infections with CC/MCC
Source: CMS MS-DRG v44.0 and FY2027 IPPS final rule. Page updated September 29, 2026.
- Relative weight
- 1.2255
- Geometric mean LOS
- 4.1 days
- Arithmetic mean LOS
- 5.6 days
- Type
- Medical
About MS-DRG 121
MS-DRG 121, Acute Major Eye Infections with CC/MCC, is a medical DRG in MDC 02 (Diseases and Disorders of the Eye) under MS-DRG version 44.0, which applies to inpatient discharges from October 1, 2026 through September 30, 2027.
Its FY2027 relative weight is 1.2255, so Medicare's base payment for this DRG is about 1.23 times the average inpatient case, before hospital-specific adjustments. The geometric mean length of stay is 4.1 days and the arithmetic mean is 5.6 days.
It belongs to a 2-level severity family: DRG 121 (with CC/MCC, weight 1.2255) and DRG 122 (without CC/MCC, weight 0.7406). The highest-severity level carries 1.7 times the weight of the lowest, which is why documenting CC and MCC conditions matters.
77 ICD-10-CM diagnosis codes are part of this DRG's grouping logic; they are listed below.
ICD-10-CM codes that group to DRG 121 (77)
Chapter 7: Diseases of the eye and adnexa
- H04.011Acute dacryoadenitis, right lacrimal gland
- H04.012Acute dacryoadenitis, left lacrimal gland
- H04.013Acute dacryoadenitis, bilateral lacrimal glands
- H04.019Acute dacryoadenitis, unspecified lacrimal gland
- H04.321Acute dacryocystitis of right lacrimal passage
- H04.322Acute dacryocystitis of left lacrimal passage
- H04.323Acute dacryocystitis of bilateral lacrimal passages
- H04.329Acute dacryocystitis of unspecified lacrimal passage
- H04.331Acute lacrimal canaliculitis of right lacrimal passage
- H04.332Acute lacrimal canaliculitis of left lacrimal passage
- H04.333Acute lacrimal canaliculitis of bilateral lacrimal passages
- H04.339Acute lacrimal canaliculitis of unspecified lacrimal passage
- H05.011Cellulitis of right orbit
- H05.012Cellulitis of left orbit
- H05.013Cellulitis of bilateral orbits
- H05.019Cellulitis of unspecified orbit
- H05.021Osteomyelitis of right orbit
- H05.022Osteomyelitis of left orbit
- H05.023Osteomyelitis of bilateral orbits
- H05.029Osteomyelitis of unspecified orbit
- H05.031Periostitis of right orbit
- H05.032Periostitis of left orbit
- H05.033Periostitis of bilateral orbits
- H05.039Periostitis of unspecified orbit
- H05.041Tenonitis of right orbit
- H05.042Tenonitis of left orbit
- H05.043Tenonitis of bilateral orbits
- H05.049Tenonitis of unspecified orbit
- H16.001Unspecified corneal ulcer, right eye
- H16.002Unspecified corneal ulcer, left eye
- H16.003Unspecified corneal ulcer, bilateral
- H16.009Unspecified corneal ulcer, unspecified eye
- H16.011Central corneal ulcer, right eye
- H16.012Central corneal ulcer, left eye
- H16.013Central corneal ulcer, bilateral
- H16.019Central corneal ulcer, unspecified eye
- H16.031Corneal ulcer with hypopyon, right eye
- H16.032Corneal ulcer with hypopyon, left eye
- H16.033Corneal ulcer with hypopyon, bilateral
- H16.039Corneal ulcer with hypopyon, unspecified eye
- H16.061Mycotic corneal ulcer, right eye
- H16.062Mycotic corneal ulcer, left eye
- H16.063Mycotic corneal ulcer, bilateral
- H16.069Mycotic corneal ulcer, unspecified eye
- H16.071Perforated corneal ulcer, right eye
- H16.072Perforated corneal ulcer, left eye
- H16.073Perforated corneal ulcer, bilateral
- H16.079Perforated corneal ulcer, unspecified eye
- H16.311Corneal abscess, right eye
- H16.312Corneal abscess, left eye
- H16.313Corneal abscess, bilateral
- H16.319Corneal abscess, unspecified eye
- H21.331Parasitic cyst of iris, ciliary body or anterior chamber, right eye
- H21.332Parasitic cyst of iris, ciliary body or anterior chamber, left eye
- H21.333Parasitic cyst of iris, ciliary body or anterior chamber, bilateral
- H21.339Parasitic cyst of iris, ciliary body or anterior chamber, unspecified eye
- H33.121Parasitic cyst of retina, right eye
- H33.122Parasitic cyst of retina, left eye
- H33.123Parasitic cyst of retina, bilateral
- H33.129Parasitic cyst of retina, unspecified eye
- H44.001Unspecified purulent endophthalmitis, right eye
- H44.002Unspecified purulent endophthalmitis, left eye
- H44.003Unspecified purulent endophthalmitis, bilateral
- H44.009Unspecified purulent endophthalmitis, unspecified eye
- H44.011Panophthalmitis (acute), right eye
- H44.012Panophthalmitis (acute), left eye
- H44.013Panophthalmitis (acute), bilateral
- H44.019Panophthalmitis (acute), unspecified eye
- H44.021Vitreous abscess (chronic), right eye
- H44.022Vitreous abscess (chronic), left eye
- H44.023Vitreous abscess (chronic), bilateral
- H44.029Vitreous abscess (chronic), unspecified eye
- H44.121Parasitic endophthalmitis, unspecified, right eye
- H44.122Parasitic endophthalmitis, unspecified, left eye
- H44.123Parasitic endophthalmitis, unspecified, bilateral
- H44.129Parasitic endophthalmitis, unspecified, unspecified eye
- H44.19Other endophthalmitis
Common questions about DRG 121
What is the relative weight of DRG 121?
- 1.2255 for FY2027 (MS-DRG v44.0), from the IPPS final rule Table 5.
What is the average length of stay for DRG 121?
- The geometric mean length of stay is 4.1 days; the arithmetic mean is 5.6 days.
Is DRG 121 medical or surgical?
- DRG 121 is a medical DRG.