Q99.2 — Fragile X chromosome
Q99.2 is a billable, specific ICD-10-CM code for fragile x chromosome. It is valid for submission on a claim.
Inclusion terms
Alternative wordings a physician may use in the chart for this same code.
- Fragile X syndrome
Risk adjustment
Q99.2 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.
Medicare coverage
Q99.2 is named in 4 Medicare coverage policies — 4 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A53060Billing and Coding: Ophthalmology: Extended Ophthalmoscopy and Fundus Photography
- A56726Billing and Coding: Ophthalmology: Posterior Segment Imaging (Extended Ophthalmoscopy and Fundus Photography)
- A57071Billing and Coding: Ophthalmology: Posterior Segment Imaging (Extended Ophthalmoscopy and Fundus Photography)
- A57204Billing and Coding: MRI and CT Scans of the Head and Neck
How Q99.2 is indexed
Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to Q99.2.
- Fragile, fragility›X chromosome
- Syndrome›fragile X
Related codes at this level
Codes that share Q99. If Q99.2 is not quite right, the correct code is usually one of these.
Questions about Q99.2
- Is Q99.2 a billable ICD-10-CM code?
- Yes. Q99.2 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does Q99.2 sit in the tabular list?
- Congenital malformations, deformations and chromosomal abnormalities (Q00-QA0), in the block Chromosomal abnormalities, not elsewhere classified (Q90-Q99).