G47.21 — Circadian rhythm sleep disorder, delayed sleep phase type
G47.21 is a billable, specific ICD-10-CM code for circadian rhythm sleep disorder, delayed sleep phase type. It is valid for submission on a claim.
Inclusion terms
Alternative wordings a physician may use in the chart for this same code.
- Delayed sleep phase syndrome
Risk adjustment
G47.21 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
G47.21 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.
- A56730Billing and Coding: Respiratory Therapy and Oximetry Services
- A56923Billing and Coding: Outpatient Sleep Studies
- A57130Billing and Coding: Psychiatric Codes
- A57326Billing and Coding: Electrocardiograms
How G47.21 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 G47.21.
- Delay, delayed›sleep phase syndrome
- Syndrome›delayed sleep phase
- Disorder›sleep›circadian rhythm›delayed sleep phase type
Related codes at this level
Codes that share G47.2. If G47.21 is not quite right, the correct code is usually one of these.
- G47.20Circadian rhythm sleep disorder, unspecified type
- G47.22Circadian rhythm sleep disorder, advanced sleep phase type
- G47.23Circadian rhythm sleep disorder, irregular sleep wake type
- G47.24Circadian rhythm sleep disorder, free running type
- G47.25Circadian rhythm sleep disorder, jet lag type
- G47.26Circadian rhythm sleep disorder, shift work type
- G47.27Circadian rhythm sleep disorder in conditions classified elsewhere
- G47.29Other circadian rhythm sleep disorder
Questions about G47.21
- Is G47.21 a billable ICD-10-CM code?
- Yes. G47.21 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does G47.21 sit in the tabular list?
- Diseases of the nervous system (G00-G99), in the block Episodic and paroxysmal disorders (G40-G47).