ICD↔CPT crosswalk
CPT 0166U: ICD-10 codes that support medical necessity
These ICD-10-CM diagnoses support medical necessity for CPT 0166U under Medicare coverage policies (LCDs, NCDs, and Billing & Coding articles). Billing CPT 0166U with a diagnosis that isn't covered typically denies as CARC 50 — not medically necessary.
National approximation. Coverage varies by MAC and state — confirm against the specific LCD/NCD and article that applies to your jurisdiction and date of service.
| ICD-10 | Description |
|---|---|
| E11.00 | Type 2 diabetes mellitus with hyperosmolarity without nonketotic hyperglycemic-hyperosmolar coma (NKHHC) |
| E11.01 | Type 2 diabetes mellitus with hyperosmolarity with coma |
| E11.10 | Type 2 diabetes mellitus with ketoacidosis without coma |
| E11.11 | Type 2 diabetes mellitus with ketoacidosis with coma |
| E11.21 | Type 2 diabetes mellitus with diabetic nephropathy |
| E11.22 | Type 2 diabetes mellitus with diabetic chronic kidney disease |
| E11.29 | Type 2 diabetes mellitus with other diabetic kidney complication |
| E11.311 | Type 2 diabetes mellitus with unspecified diabetic retinopathy with macular edema |
| E11.319 | Type 2 diabetes mellitus with unspecified diabetic retinopathy without macular edema |
| E11.3211 | Type 2 diabetes mellitus with mild nonproliferative diabetic retinopathy with macular edema, right eye |
| E11.3212 | Type 2 diabetes mellitus with mild nonproliferative diabetic retinopathy with macular edema, left eye |
| E11.3213 | Type 2 diabetes mellitus with mild nonproliferative diabetic retinopathy with macular edema, bilateral |
| E11.3219 | Type 2 diabetes mellitus with mild nonproliferative diabetic retinopathy with macular edema, unspecified eye |
| E11.3291 | Type 2 diabetes mellitus with mild nonproliferative diabetic retinopathy without macular edema, right eye |
| E11.3292 | Type 2 diabetes mellitus with mild nonproliferative diabetic retinopathy without macular edema, left eye |
| E11.3293 | Type 2 diabetes mellitus with mild nonproliferative diabetic retinopathy without macular edema, bilateral |
| E11.3299 | Type 2 diabetes mellitus with mild nonproliferative diabetic retinopathy without macular edema, unspecified eye |
| E11.3311 | Type 2 diabetes mellitus with moderate nonproliferative diabetic retinopathy with macular edema, right eye |
| E11.3312 | Type 2 diabetes mellitus with moderate nonproliferative diabetic retinopathy with macular edema, left eye |
| E11.3313 | Type 2 diabetes mellitus with moderate nonproliferative diabetic retinopathy with macular edema, bilateral |
| E11.3319 | Type 2 diabetes mellitus with moderate nonproliferative diabetic retinopathy with macular edema, unspecified eye |
| E11.3391 | Type 2 diabetes mellitus with moderate nonproliferative diabetic retinopathy without macular edema, right eye |
| E11.3392 | Type 2 diabetes mellitus with moderate nonproliferative diabetic retinopathy without macular edema, left eye |
| E11.3393 | Type 2 diabetes mellitus with moderate nonproliferative diabetic retinopathy without macular edema, bilateral |
| E11.3399 | Type 2 diabetes mellitus with moderate nonproliferative diabetic retinopathy without macular edema, unspecified eye |
| E11.3411 | Type 2 diabetes mellitus with severe nonproliferative diabetic retinopathy with macular edema, right eye |
| E11.3412 | Type 2 diabetes mellitus with severe nonproliferative diabetic retinopathy with macular edema, left eye |
| E11.3413 | Type 2 diabetes mellitus with severe nonproliferative diabetic retinopathy with macular edema, bilateral |
| E11.3419 | Type 2 diabetes mellitus with severe nonproliferative diabetic retinopathy with macular edema, unspecified eye |
| E11.3491 | Type 2 diabetes mellitus with severe nonproliferative diabetic retinopathy without macular edema, right eye |
| E11.3492 | Type 2 diabetes mellitus with severe nonproliferative diabetic retinopathy without macular edema, left eye |
| E11.3493 | Type 2 diabetes mellitus with severe nonproliferative diabetic retinopathy without macular edema, bilateral |
| E11.3499 | Type 2 diabetes mellitus with severe nonproliferative diabetic retinopathy without macular edema, unspecified eye |
| E11.3511 | Type 2 diabetes mellitus with proliferative diabetic retinopathy with macular edema, right eye |
| E11.3512 | Type 2 diabetes mellitus with proliferative diabetic retinopathy with macular edema, left eye |
| E11.3513 | Type 2 diabetes mellitus with proliferative diabetic retinopathy with macular edema, bilateral |
| E11.3519 | Type 2 diabetes mellitus with proliferative diabetic retinopathy with macular edema, unspecified eye |
| E11.3521 | Type 2 diabetes mellitus with proliferative diabetic retinopathy with traction retinal detachment involving the macula, right eye |
| E11.3522 | Type 2 diabetes mellitus with proliferative diabetic retinopathy with traction retinal detachment involving the macula, left eye |
| E11.3523 | Type 2 diabetes mellitus with proliferative diabetic retinopathy with traction retinal detachment involving the macula, bilateral |
| E11.3529 | Type 2 diabetes mellitus with proliferative diabetic retinopathy with traction retinal detachment involving the macula, unspecified eye |
| E11.3531 | Type 2 diabetes mellitus with proliferative diabetic retinopathy with traction retinal detachment not involving the macula, right eye |
| E11.3532 | Type 2 diabetes mellitus with proliferative diabetic retinopathy with traction retinal detachment not involving the macula, left eye |
| E11.3533 | Type 2 diabetes mellitus with proliferative diabetic retinopathy with traction retinal detachment not involving the macula, bilateral |
| E11.3539 | Type 2 diabetes mellitus with proliferative diabetic retinopathy with traction retinal detachment not involving the macula, unspecified eye |
| E11.3541 | Type 2 diabetes mellitus with proliferative diabetic retinopathy with combined traction retinal detachment and rhegmatogenous retinal detachment, right eye |
| E11.3542 | Type 2 diabetes mellitus with proliferative diabetic retinopathy with combined traction retinal detachment and rhegmatogenous retinal detachment, left eye |
| E11.3543 | Type 2 diabetes mellitus with proliferative diabetic retinopathy with combined traction retinal detachment and rhegmatogenous retinal detachment, bilateral |
| E11.3549 | Type 2 diabetes mellitus with proliferative diabetic retinopathy with combined traction retinal detachment and rhegmatogenous retinal detachment, unspecified eye |
| E11.3551 | Type 2 diabetes mellitus with stable proliferative diabetic retinopathy, right eye |
| E11.3552 | Type 2 diabetes mellitus with stable proliferative diabetic retinopathy, left eye |
| E11.3553 | Type 2 diabetes mellitus with stable proliferative diabetic retinopathy, bilateral |
| E11.3559 | Type 2 diabetes mellitus with stable proliferative diabetic retinopathy, unspecified eye |
| E11.3591 | Type 2 diabetes mellitus with proliferative diabetic retinopathy without macular edema, right eye |
| E11.3592 | Type 2 diabetes mellitus with proliferative diabetic retinopathy without macular edema, left eye |
| E11.3593 | Type 2 diabetes mellitus with proliferative diabetic retinopathy without macular edema, bilateral |
| E11.3599 | Type 2 diabetes mellitus with proliferative diabetic retinopathy without macular edema, unspecified eye |
| E11.36 | Type 2 diabetes mellitus with diabetic cataract |
| E11.37X1 | Type 2 diabetes mellitus with diabetic macular edema, resolved following treatment, right eye |
| E11.37X2 | Type 2 diabetes mellitus with diabetic macular edema, resolved following treatment, left eye |
| E11.37X3 | Type 2 diabetes mellitus with diabetic macular edema, resolved following treatment, bilateral |
| E11.37X9 | Type 2 diabetes mellitus with diabetic macular edema, resolved following treatment, unspecified eye |
| E11.39 | Type 2 diabetes mellitus with other diabetic ophthalmic complication |
| E11.40 | Type 2 diabetes mellitus with diabetic neuropathy, unspecified |
| E11.41 | Type 2 diabetes mellitus with diabetic mononeuropathy |
| E11.42 | Type 2 diabetes mellitus with diabetic polyneuropathy |
| E11.43 | Type 2 diabetes mellitus with diabetic autonomic (poly)neuropathy |
| E11.44 | Type 2 diabetes mellitus with diabetic amyotrophy |
| E11.49 | Type 2 diabetes mellitus with other diabetic neurological complication |
| E11.51 | Type 2 diabetes mellitus with diabetic peripheral angiopathy without gangrene |
| E11.52 | Type 2 diabetes mellitus with diabetic peripheral angiopathy with gangrene |
| E11.59 | Type 2 diabetes mellitus with other circulatory complications |
| E11.610 | Type 2 diabetes mellitus with diabetic neuropathic arthropathy |
| E11.618 | Type 2 diabetes mellitus with other diabetic arthropathy |
| E11.620 | Type 2 diabetes mellitus with diabetic dermatitis |
| E11.621 | Type 2 diabetes mellitus with foot ulcer |
| E11.622 | Type 2 diabetes mellitus with other skin ulcer |
| E11.628 | Type 2 diabetes mellitus with other skin complications |
| E11.630 | Type 2 diabetes mellitus with periodontal disease |
| E11.638 | Type 2 diabetes mellitus with other oral complications |
| E11.641 | Type 2 diabetes mellitus with hypoglycemia with coma |
| E11.649 | Type 2 diabetes mellitus with hypoglycemia without coma |
| E11.65 | Type 2 diabetes mellitus with hyperglycemia |
| E11.69 | Type 2 diabetes mellitus with other specified complication |
| E11.8 | Type 2 diabetes mellitus with unspecified complications |
| E11.9 | Type 2 diabetes mellitus without complications |
| E66.3 | Overweight |
| E66.811 | Obesity, class 1 |
| E66.812 | Obesity, class 2 |
| E66.813 | Obesity, class 3 |
| E66.89 | Other obesity not elsewhere classified |
| E66.9 | Obesity, unspecified |
| E78.00 | Pure hypercholesterolemia, unspecified |
| E78.010 | Homozygous familial hypercholesterolemia [HoFH] |
| E78.011 | Heterozygous familial hypercholesterolemia [HeFH] |
| E78.019 | Familial hypercholesterolemia, unspecified |
| E78.2 | Mixed hyperlipidemia |
| E78.5 | Hyperlipidemia, unspecified |
| I10 | Essential (primary) hypertension |
| I1A.0 | Resistant hypertension |
| K74.00 | Hepatic fibrosis, unspecified |
| K74.01 | Hepatic fibrosis, early fibrosis |
| K74.02 | Hepatic fibrosis, advanced fibrosis |
| K75.81 | Nonalcoholic steatohepatitis (NASH) |
| K76.0 | Fatty (change of) liver, not elsewhere classified |
| R73.01 | Impaired fasting glucose |
| R73.02 | Impaired glucose tolerance (oral) |
| R73.03 | Prediabetes |
| R73.09 | Other abnormal glucose |
| R73.9 | Hyperglycemia, unspecified |
| R74.01 | Elevation of levels of liver transaminase levels |
| R94.5 | Abnormal results of liver function studies |
| Z79.4 | Long term (current) use of insulin |
| Z79.84 | Long term (current) use of oral hypoglycemic drugs |
| Z79.85 | Long-term (current) use of injectable non-insulin antidiabetic drugs |
Frequently asked questions
Which ICD-10 codes support medical necessity for CPT 0166U?
Medicare coverage policies (LCDs/NCDs and Billing & Coding articles) list 115 ICD-10 diagnosis codes that support medical necessity for CPT 0166U. The covered codes are listed on this page. Coverage varies by MAC/state — always confirm against the policy that applies to you.
What is a medical-necessity (LCD/NCD) crosswalk?
A claim whose procedure isn't supported by a covered diagnosis denies as "not medically necessary" (CARC 50). CMS coverage policies define which diagnoses justify a procedure; this page is the ICD-10 → CPT 0166U view of that relationship.
Catch medical-necessity denials before you bill. CareNiva scrubs claims against LCD/NCD coverage and flags unsupported diagnoses — in the same platform you run visits and billing.
More free billing tools: all crosswalks · NCCI edits · Medicare fees · denial codes
Informational only, not coding, billing, or legal advice. Based on CMS Medicare Coverage Database data; verify the current LCD/NCD for your MAC before billing.
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