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E55.9ICD-10-CM

Vitamin D deficiency, unspecified

BillableThree Excludes1 notes sit above the codeNo separate insufficiency code exists

How the code is built

E

Chapter

Endocrine, nutritional and metabolic diseases

55

Category

Vitamin D deficiency

9

Char 4

No active rickets documented

Chapter

E00 to E89

Endocrine, nutritional and metabolic diseases

Block

E50 to E64

Other nutritional deficiencies

Category

E55

Vitamin D deficiency, not billable on its own

Billable

Yes

Complete at 4 characters

Inclusion term

Avitaminosis D

Classifies here

Excludes1 at E55

Adult osteomalacia, osteoporosis with fracture, sequelae of rickets

All inherited, none on the code line

Excludes2 at E50 to E64

Nutritional anemias

A permission, not a prohibition

DefinitionCode structureClinical pictureDocumentationDecision guideTabular listComparisonClaim contextDenialsSources

Key takeaways

  • E55.9 codes vitamin D deficiency when active rickets is not documented, and avitaminosis D classifies here
  • The category has only two children, so the choice is between active rickets and everything else
  • There is no code for vitamin D insufficiency, so borderline and frank deficiency report identically
  • Three Excludes1 notes reach this code from the category, and none appear on the code line
  • It is billable, and the testing it supports is one of the most closely reviewed laboratory services in outpatient billing
1Definition

What ICD-10 code E55.9 means

E55.9 is the ICD-10-CM code for vitamin D deficiency, unspecified. It applies when a provider documents vitamin D deficiency without active rickets, which covers essentially every adult encounter and most pediatric ones.

Avitaminosis D is the inclusion term. The Alphabetic Index also routes several historical terms here, including calciferol deficiency and ergosterol deficiency, so older phrasing lands in the right place.

Code

E55.9

Descriptor

Vitamin D deficiency, unspecified

Chapter

Endocrine, nutritional and metabolic diseases

Block

Other nutritional deficiencies

Category

E55, vitamin D deficiency

Billable

Yes

Inclusion term

Avitaminosis D

Siblings

E55.0, rickets, active

There is no code for vitamin D insufficiency. The distinction clinicians draw between insufficiency and frank deficiency, based on where the serum level falls, has no counterpart in the classification. A patient at the low end of the reference range and a patient with a markedly deficient level report the same four characters. So does a note saying only low vitamin D.

That has a practical consequence. The specificity argument that drives most unspecified codes does not exist here, because there is nothing more specific to reach for unless rickets is present. What matters instead is whether the diagnosis belongs on the claim at all, and whether the testing that produced it was covered.

2Code structure

A two-code category, and where the neighbours take over

E55.9 has no subdivisions, and E55 has only two children.

The category, in full

Vitamin D deficiency, no active rickets

E55.9

Active rickets

E55.0

Where the related conditions actually live

Infantile or juvenile osteomalacia

Code

E55.0

Relationship to E55.9

Inclusion term at active rickets

Adult osteomalacia

Code

M83.-

Relationship to E55.9

Excludes1, prohibited alongside

Sequelae of rickets

Code

E64.3

Relationship to E55.9

Excludes1, prohibited alongside

Osteoporosis with current pathological fracture

Code

M80.-

Relationship to E55.9

Excludes1, prohibited alongside

Osteoporosis without current pathological fracture

Code

M81.-

Relationship to E55.9

Not named in the note

Vitamin D-resistant rickets or osteomalacia

Code

E83.3

Relationship to E55.9

A phosphorus metabolism disorder, not a deficiency

Dietary calcium deficiency

Code

E58

Relationship to E55.9

A separate nutritional deficiency

Nutritional anemias

Code

D50 to D53

Relationship to E55.9

Excludes2 at the block, reportable alongside

Osteomalacia is split by age across two chapters, and the split matters. Infantile and juvenile osteomalacia are inclusion terms at E55.0, so in a child the condition classifies as a nutritional deficiency. Adult osteomalacia classifies to the musculoskeletal chapter and is expressly prohibited alongside E55.9. The same clinical word goes to different chapters depending on the patient's age, and only one of those pairings is codable with a vitamin D deficiency code.

3Clinical picture

Clinical findings documented under E55.9

Vitamin D deficiency is often asymptomatic and identified on testing, which shapes what a supporting record contains.

Laboratory

Serum 25-hydroxyvitamin D level, with calcium, phosphate, alkaline phosphatase, and parathyroid hormone where obtained

Musculoskeletal

Diffuse bone pain, muscle weakness, proximal myopathy, difficulty rising from a chair

Skeletal findings

Fracture history, low bone density, and in children bowing, delayed closure of fontanelles, or growth delay

Risk factors

Limited sun exposure, malabsorption, bariatric surgery, chronic kidney or liver disease, certain anticonvulsants

Consequences

Secondary hyperparathyroidism, hypocalcemia

Treatment

Repletion dosing and the follow-up testing interval

Skeletal deformity in a child is the finding that moves the code, since active rickets belongs at E55.0. In an adult, documented osteomalacia moves the encounter out of this category entirely.

4Documentation

What the chart must show

  • A provider-stated diagnosis of vitamin D deficiency, not a laboratory value alone
  • The serum 25-hydroxyvitamin D result that established it
  • The clinical indication for testing, stated before the result rather than justified afterward
  • Any condition causing malabsorption or interfering with metabolism
  • Symptoms attributable to the deficiency, where present
  • Whether active rickets or osteomalacia is present
  • Repletion therapy and the monitoring plan
  • Whether the encounter is diagnostic or a follow-up of a known deficiency

The indication is the element that carries the claim. Because there is no more specific code to reach for, the exposure on E55.9 is not vagueness. It is whether the record establishes a reason to have tested at all, and that reason has to predate the abnormal result.

5Decision guide

When to assign E55.9, and when not to

Vitamin D deficiency, no rickets

E55.9

Vitamin D insufficiency, or low vitamin D

E55.9, since no insufficiency code exists

Avitaminosis D

E55.9

Active rickets

E55.0

Infantile or juvenile osteomalacia

E55.0

Adult osteomalacia

M83.-, never with E55.9

Sequelae of rickets

E64.3, never with E55.9

Osteoporosis with a current pathological fracture

M80.-, never with E55.9

Osteoporosis without a current pathological fracture

M81.-, which the note does not name

Vitamin D-resistant rickets or osteomalacia

E83.3

Dietary calcium deficiency

E58

Renal osteodystrophy

N25.0

Multiple vitamin deficiency

E56.9

A low result with no diagnosis stated

Query, since a laboratory value is not a diagnosis

Screening in an asymptomatic patient

The screening encounter code, not E55.9

There is no sequencing rule attached to E55.9. The decisions are whether rickets is present, whether an Excludes1 condition displaces the code, and whether the encounter is diagnostic or screening.

Query rather than default when a low result appears with no comment in the assessment, and when bone pain or weakness is documented without a statement connecting it to the deficiency.

6Tabular list

Instructional notes at E55 and above

Inclusion term at E55.9

Avitaminosis D

Inclusion terms at E55.0

Infantile osteomalacia, juvenile osteomalacia

Excludes1 at E55

Adult osteomalacia (M83.-)

Excludes1 at E55

Osteoporosis (M80.-)

Excludes1 at E55

Sequelae of rickets (E64.3)

Excludes2 at E50 to E64

Nutritional anemias (D50 to D53)

All three prohibitions are inherited. E55.9 carries an inclusion term and nothing else, so a coder verifying the code entry alone will conclude it is unconstrained. The Excludes1 notes sit one level up at the category.

The osteoporosis exclusion is narrower than it looks, and the difference is worth knowing. The note names osteoporosis at M80, which is osteoporosis with a current pathological fracture. It does not name M81, which is osteoporosis without a current pathological fracture. On the face of the tabular list, then, E55.9 and a code for osteoporosis without fracture are not a prohibited pair, while E55.9 and a fracture-bearing osteoporosis code are. Given how routinely vitamin D deficiency and osteoporosis are documented together, this is a distinction to confirm against your payer's edits rather than assume in either direction.

The nutritional anemia note is a permission. It is an Excludes2 at the block, so a patient with both a nutritional anemia and vitamin D deficiency may carry codes from each.

7Comparison

Codes frequently confused with E55.9

E55.0

Descriptor

Rickets, active

Use instead when

Active rickets, or infantile or juvenile osteomalacia, is documented

M83.-

Descriptor

Adult osteomalacia, including puerperal, senile, and malabsorption forms

Use instead when

Adult osteomalacia is documented, which the Excludes1 blocks

M80.-

Descriptor

Osteoporosis with current pathological fracture

Use instead when

A pathological fracture is present, which the Excludes1 blocks

M81.-

Descriptor

Osteoporosis without current pathological fracture, including age-related and localized

Use instead when

Osteoporosis is present without a current fracture

E64.3

Descriptor

Sequelae of rickets

Use instead when

Residual effects of resolved rickets are documented, which the Excludes1 blocks

E83.3

Descriptor

Disorders of phosphorus metabolism and phosphatases

Use instead when

Vitamin D-resistant rickets or osteomalacia is documented

E58

Descriptor

Dietary calcium deficiency

Use instead when

Calcium rather than vitamin D is the deficiency

E56.9

Descriptor

Vitamin deficiency, unspecified

Use instead when

Multiple or unspecified vitamin deficiency is documented

N25.0

Descriptor

Renal osteodystrophy

Use instead when

Bone disease from chronic kidney disease is documented

D50 to D53

Descriptor

Nutritional anemias

Use instead when

A nutritional anemia is documented, reportable alongside

E20.-

Descriptor

Hypoparathyroidism

Use instead when

A parathyroid disorder is the diagnosis

E21.-

Descriptor

Hyperparathyroidism

Use instead when

Secondary hyperparathyroidism is documented as a diagnosis

The E83.3 row is worth pausing on. Vitamin D-resistant rickets and vitamin D-resistant osteomalacia are not vitamin D deficiencies. They are disorders of phosphorus metabolism; they classify in a different category, and the word resistant is what redirects them.

8Claim context

Services commonly reported with E55.9

E55.9 supports primary care and specialty evaluation and management, the serum 25-hydroxyvitamin D testing that identifies and monitors the deficiency, and bone density testing where osteoporosis is also a question.

Vitamin D testing is not among the twenty-three national laboratory determinations, so coverage and frequency are set contractor by contractor. Those policies list the conditions that support testing, and they are narrower than clinical practice. Screening an asymptomatic patient is generally not covered, because Medicare pays for screening only where a statute creates the benefit and no such benefit exists for vitamin D.

That produces the pattern specific to this code. A test ordered on a patient with no documented risk factor or symptom returns a low result; the result becomes the diagnosis, and the diagnosis is then reported as the indication for the test that discovered it. Reviewers read the order date. The indication has to exist in the record before the specimen is drawn.

Follow-up testing during repletion is on firmer ground, since monitoring a documented deficiency is a recognized indication in most contractor policies. Even so, the interval matters, and repeat panels drawn more often than the policy contemplates need a documented reason. Confirm the applicable local coverage determination before submitting serial testing.

9Denials

Coding errors that cause denials

Using E55.9 as the indication for the test that found the deficiency

Report the documented risk factor or symptom that prompted the order

Coding E55.9 for a screening test on an asymptomatic patient

Report the screening encounter code

Assigning E55.9 from a laboratory value with no provider diagnosis

Query, since a result is not a diagnosis

Reporting E55.9 with adult osteomalacia

Choose one, since the Excludes1 prohibits the pair

Reporting E55.9 with a fracture-bearing osteoporosis code

Choose one, since the Excludes1 names M80

Reporting E55.9 with sequelae of rickets

Choose one, since the Excludes1 prohibits the pair

Coding E55.9 for active rickets or for infantile or juvenile osteomalacia

Assign E55.0

Coding vitamin D-resistant rickets or osteomalacia to E55.9

Assign E83.3

Searching for an insufficiency code

Report E55.9, since none exists

Billing serial testing with no documented monitoring plan

Record the repletion course and the interval rationale

10Sources

Where to verify E55.9

ICD-10-CM Official Guidelines for Coding and Reporting

The Excludes1 and Excludes2 definitions, the rules on coding from abnormal findings, and the distinction between screening and diagnostic encounters

ICD-10-CM Tabular List at E55 and the E50 to E64 block

The three inherited Excludes1 notes, the inclusion terms at both children, and the block Excludes2

CMS ICD-10 code page and the FY 2026 files

Current code files and the annual addenda

Laboratory NCD list

Confirms vitamin D testing is not among the twenty-three national laboratory policies, so coverage is contractor-specific

Medicare Coverage Database

Search your contractor's determination for vitamin D assay, including the covered indications and testing frequency.

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Last reviewed August 2026

This page is a free reference for billing and coding teams and is not coding, legal, or clinical advice. Code selection depends on the documentation in the record and on the policy of the payer being billed. Verify every code, instructional note, and sequencing rule against the current ICD-10-CM files and the Official Guidelines for Coding and Reporting for the applicable date of service. ICD-10-CM is maintained by the CDC's National Center for Health Statistics and published by CMS. CPT is a registered trademark of the American Medical Association. TruCare is not affiliated with CMS, NCHS, the AHA, or the AMA.

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