ICD-10 Z23 is officially defined as "Encounter for immunization." code Z23 is referenced in 28 tracked payer policy changes from Blue Cross Blue Shield of North Dakota, Aetna, and 2 other payers. For billers and coders, staying current on payer-specific coverage criteria, reimbursement rules, and prior-authorization requirements for code Z23 is critical to clean claim submission. Each entry below links to the full policy analysis with effective dates and action steps.
BCBSND issued updated billing requirements for immunization season. Key changes include: bill immunizations on CMS-1500 forms (even for inpatients using POS 21), use modifier 59 when billing influenza and COVID vaccines together with codes 90471 and 90480, and ensure proper diagnosis coding with ICD-10 Z23.
Aetna Clinical Policy Bulletin 0723 (last review 10/20/2026) considers the FDA-approved rotavirus vaccines RotaTeq and Rotarix medically necessary for prevention of rotavirus gastroenteritis in infants less than 8 months of age, based on ACIP recommendations. It considers rotavirus vaccines experimental, investigational, or unproven for all other indications. CPT 90680 and 90681, and ICD-10 Z23, are listed as covered if selection criteria are met.
The 2026-2027 vaccine formula targets the JN.1 lineage, and the FDA preferentially recommends the LP.8.1 strain. NC Medicaid covers Comirnaty for ages five and older, Spikevax for ages 6 months and older, and Nuvaxovid and mNexspike for ages 12 and older, each as a medical or pharmacy point-of-sale claim. Beneficiaries ages 18 and younger in the Vaccines for Children program receive COVID-19 vaccines through VFC, and the NDCs and CPT codes for each product are listed in the billing table.
The 2026-2027 influenza season billing rules for NC Medicaid Direct and NC Medicaid Managed Care health plans set which flu vaccine products are covered by age, from FluMist for ages 2 through 49 to Flublok for ages 9 and older. Claims must report the ICD-10 code Z23 and the NDC that matches the vaccine given, along with both a vaccine CPT code and an administration CPT code, because claims must contain both to pay. For VFC-eligible children through age 18, providers report the vaccine code with $0.00 and bill only the administration fee.
Aetna considers immune globulins medically necessary for hepatitis B, cytomegalovirus, Rho-D, rabies, varicella zoster, tetanus, vaccinia, botulism, hepatitis A, measles (rubeola) and rubella exposures or conditions, and considers all other indications experimental, investigational, or unproven. Each product has its own initial criteria, such as hepatitis B immune globulin for members who had contact with an individual diagnosed with hepatitis B virus, Rho-D immune globulin for unsensitized Rh-negative women at 24 to 28 weeks gestation unless the father is known to be Rh-negative, and varicella zoster immune globulin for high-risk individuals with significant exposure to varicella. Continuation of therapy for each product is considered medically necessary for all members, including new members, who meet all initial medical necessity criteria.
Aetna considers FDA-approved influenza vaccines medically necessary when the product matches the member's age: standard or preservative-free trivalent injectables such as Afluria, Fluarix, Flucelvax and Fluzone for members 6 months of age or older, Flublok for members 9 years of age or older, Fluad and Fluzone High-Dose for members 65 years of age and older, mFLUSIVA mRNA trivalent injectable for members 50 years of age or older, and FluMist trivalent intranasal vaccine for members 2 through 49 years of age. The CDC does not recommend FluMist for individuals who are pregnant or immunocompromised, or who have certain medical conditions such as asthma. CPT 90664 (pandemic formulation live influenza vaccine) and ICD-10 codes for immune mechanism disorders, asthma and pregnancy are listed as not covered for the indications in the policy. For the 2025-2026 season, the CDC recommends an updated flu vaccine for everyone 6 months of age and older, with rare exceptions.
Aetna considers FDA-approved pneumococcal conjugate vaccines (PCV15, PCV20, PCV21) and pneumococcal polysaccharide vaccine (PPSV23) medically necessary according to CDC ACIP recommendations for specified groups. Those groups include all children aged 2 through 59 months, children and adolescents who meet the listed risk-condition and catch-up criteria, adults 50 years of age or older who have not previously received a pneumococcal conjugate vaccine or whose vaccination history is unknown, and adults 19 through 49 years with listed underlying health conditions. Adults 65 years or older may receive PCV20 or PCV21 through shared clinical decision-making, or receive no additional pneumococcal vaccines. Aetna considers these vaccines experimental, investigational or unproven for other groups. Quantitation of Streptococcus pneumoniae antibody (IgG) is medically necessary to diagnose immunodeficiency syndromes in persons with recurrent bacterial infections and to assess eligibility for parenteral immunoglobulin replacement, and is experimental, investigational or unproven for other indications.
Aetna considers FDA-approved DTaP, Tdap, and Td vaccines medically necessary as preventive services when given according to CDC ACIP recommendations, including DTaP as a five-dose series for children younger than 7, Tdap for listed ages and during every pregnancy, and a Td or Tdap booster every 10 years after the primary series. Td or Tdap is also covered for tetanus prophylaxis in wound management when at least 5 years have elapsed since the last tetanus toxoid-containing vaccine. FDA-approved combination vaccines (Pediarix, Pentacel, Vaxelis, Kinrix, and Quadracel) may be used in place of the standalone vaccines when given according to FDA labeling and CDC/ACIP recommendations.
Aetna's Clinical Policy Bulletin 0318 covers palivizumab (Synagis) for commercial medical plans and requires precertification from participating providers and members in applicable plan designs. Aetna considers palivizumab medically necessary for up to 5 doses per RSV season to prevent serious lower respiratory tract disease caused by RSV when a member has prematurity, chronic lung disease of prematurity, hemodynamically significant congenital heart disease, a congenital airway abnormality, a neuromuscular condition that compromises handling of respiratory secretions, profound immunocompromise, or cystic fibrosis, and the age, gestational age and clinical criteria for that diagnosis are met. Palivizumab is excluded for members who received nirsevimab-alip (Beyfortus) in the same RSV season. Aetna considers the Synagis season to be November 1 through March 31. For off-season requests, 1 dose per request may be authorized, up to 5 doses per RSV season, if RSV activity for the requested region is at least 3% by real-time PCR within 2 weeks of the intended dose. Aetna considers palivizumab experimental and investigational for asthma, Down syndrome, childhood interstitial lung disease, prevention of health-care associated RSV disease, prophylaxis against RSV in immunocompromised adults, and treatment of RSV.
Aetna considers pre-exposure smallpox vaccination medically necessary when public health authorities advise it, for research laboratory personnel who work with orthopoxviruses, clinical laboratory personnel performing orthopoxvirus diagnostic testing, designated response team members at risk for occupational exposure, and healthcare personnel who administer ACAM2000 or care for persons infected with orthopoxviruses. Booster doses are covered for persons with ongoing occupational exposure to orthopoxviruses in accordance with CDC recommendations, and post-exposure smallpox vaccination is covered for persons exposed or at high risk of exposure during a public health response. Mpox vaccination with JYNNEOS is medically necessary for pre-exposure use in listed higher-risk groups and for post-exposure use in persons with known or presumed mpox exposure, and routine smallpox vaccination of the general population is not recommended.
Aetna considers several cancer vaccines experimental, investigational, or unproven because their safety and effectiveness have not been established. These include the helper multi-peptide (6MHP) vaccine for metastatic melanoma, the melanoma vaccine (also known as Theraccine or Oncophage) for any indication, HLA-A24-binding peptide vaccines for gastric cancer, the p16(INK4a)-based peptide vaccine for HPV-associated cancers, the p62 DNA vaccine (Elenagen) for solid tumors, and whole cancer stem cell-based vaccines used as an adjuvant strategy for the surgical management of solid tumors. Aetna also states that the clinical evidence is not sufficient to permit conclusions on health outcomes for tumor-associated antigenic peptide-based vaccine therapy in listed cancers, including breast, colorectal, lung, ovarian and pancreatic cancer.
Aetna Clinical Policy Bulletin 0115 covers varicella vaccine as a preventive service under the CDC ACIP recommendations, and covers the combined MMRV vaccine (ProQuad) as an alternative to separate MMR and varicella vaccines for children 12 months to 12 years where simultaneous administration of MMR and varicella vaccines is indicated. It covers the two-dose recombinant zoster vaccine Shingrix for prevention of herpes zoster in adults aged 50 years and older, in adults aged 50 years and older who previously received Zostavax, and in adults aged 18 years and older who are or will be at increased risk of herpes zoster due to immunodeficiency or immunosuppression. Shingrix is considered experimental, investigational or unproven for treatment of zoster or postherpetic neuralgia, for prevention of primary varicella infection, for repeat booster doses beyond the two-dose series and for all other indications not listed, and Zostavax is no longer available for use in the United States as of November 18, 2020.
Aetna covers medically necessary travel vaccines when the selection criteria are met. Most Aetna HMO plans exclude coverage of travel vaccines, while most Aetna traditional plans cover medically necessary travel vaccines for members of plans with preventive services benefits. Covered vaccines include chikungunya, cholera (ages 2 through 64), tick-borne encephalitis, rabies, typhoid, measles-containing vaccines (MMR and MMRV), yellow fever, Japanese encephalitis and Zaire ebolavirus vaccines. A malaria vaccine for travel and cholera vaccine for other indications are considered experimental, investigational or unproven.
Aetna considers the MenACWY, MenB and MenABCWY meningococcal vaccines medically necessary when they follow ACIP recommendations. Routine MenACWY is covered for adolescents aged 11 through 18, MenB is covered for members 10 years of age or older with listed risk factors and for healthy adolescents and young adults aged 16 through 23 based on shared clinical decision-making, and MenABCWY may be used when both MenACWY and MenB are indicated at the same visit. Meningococcal vaccine for all other indications, and saliva testing of antibody levels, are considered experimental, investigational, or unproven.
Aetna considers the FDA-approved rotavirus vaccines RotaTeq and Rotarix medically necessary for prevention of rotavirus gastroenteritis in infants less than 8 months of age, based on Centers for Disease Control and Prevention Advisory Committee on Immunization Practices recommendations. Rotavirus vaccines are considered experimental, investigational or unproven for all other indications because their effectiveness for those indications has not been established.
Aetna considers FDA-approved influenza vaccines medically necessary by age: standard or preservative-free trivalent injectables (Afluria, Fluarix, Flucelvax, Fluzone) for members 6 months of age or older, Flublok for members 9 years or older, preservative-free trivalent injectables Fluad and Fluzone High-Dose for members 65 years or older, the mRNA trivalent injectable mFLUSIVA for members 50 years or older, and the trivalent intranasal vaccine FluMist for ages 2 through 49. Aetna considers the intranasal vaccine FluMist covered under CPT 90660 when the selection criteria are met, and CPT 90664 (pandemic formulation live intranasal vaccine) is listed as not covered for the indications in the policy. Avian influenza A (H5N1) vaccines are approved by the FDA for persons at increased risk of exposure, but are not routinely available or recommended for the general U.S. population.
Reviewed 2025-12-23, Aetna Clinical Policy Bulletin 0544 covers immune globulin products for post-exposure prophylaxis and treatment, including hepatitis B, cytomegalovirus, Rho(D), rabies, varicella zoster, tetanus, measles, rubella, vaccinia, and botulism immune globulins. For each product the policy lists the indications it considers medically necessary and states that all other indications are experimental, investigational, or unproven. Continuation of therapy is considered medically necessary for all members, including new members, who meet the initial criteria. Immune globulin intramuscular injection (GamaSTAN) requires precertification.
Aetna considers hepatitis A (HepA) vaccine medically necessary for the at-risk groups in its policy, following the CDC ACIP and AAP recommendations. The listed groups include all children 12 to 23 months of age, children and adolescents aged 2 to 18 years who have not previously received HepA vaccine, persons with HIV infection aged 1 year or older, and individuals with chronic liver disease. CPT codes 90632, 90633, 90634 and 90636 are covered if selection criteria are met, and HepA vaccine is considered medically necessary for prophylaxis when initiated within 2 weeks after hepatitis A exposure.
Aetna considers hepatitis B vaccine medically necessary when it follows CDC ACIP recommendations for members with listed indications, including all infants, unvaccinated children and adolescents under 19, adults aged 19 to 59 who have not previously completed vaccination, and adults 60 and older with risk factors. Revaccination or booster doses are considered medically necessary in listed circumstances when anti-HBs is less than 10 mIU/mL, including infants born to HBsAg-positive mothers, persons on hemodialysis, and health care professionals with an anti-HBs level below that threshold. For persons with normal immune status who have been vaccinated, booster doses are considered not medically necessary. Aetna generally does not cover immunizations required for travel or because of work-related risk. The policy states that in December 2025 the CDC adopted shared clinical decision-making for hepatitis B vaccination of infants born to mothers who test negative for hepatitis B, and that existing recommendations remain unchanged for infants born to HBsAg-positive mothers or mothers with unknown status.
Aetna considers FDA-approved inactivated polio vaccine (IPV) injection medically necessary as a preventive service, according to the CDC's ACIP recommendations, for the prevention of severe polio disease, including paralysis. Oral polio vaccine is no longer recommended by ACIP and has been discontinued in the United States. ACIP recommends four IPV doses for children at 2 months, 4 months, 6 to 18 months, and 4 to 6 years, and for adults who need a primary series, two doses spaced 4 to 8 weeks apart followed by a third dose 6 to 12 months after the second.
Aetna's pneumococcal vaccine policy considers the conjugate vaccines PCV15 (Vaxneuvance), PCV20 (Prevnar 20) and PCV21 (Capvaxive) medically necessary for the age and risk groups it lists, and PPSV23 (Pneumovax 23) for the groups in its selection criteria. Coverage follows the CDC's ACIP recommendations, including the dosing rules for children, adults 19 to 49 years with underlying conditions, and adults 50 years or older. Aetna considers these vaccines experimental, investigational or unproven for other groups, and considers quantitation of Streptococcus pneumoniae IgG antibody medically necessary only to diagnose immunodeficiency in persons with recurrent bacterial infections and to assess eligibility for parenteral immunoglobulin replacement.
Aetna considers FDA-approved tetanus toxoid-containing vaccines (DTaP, Tdap or Td) medically necessary as preventive services when given according to CDC ACIP recommendations. Covered uses include a 5-dose DTaP series for children younger than 7 years, Tdap for persons 7 years or older who are not fully immunized as part of a catch-up series, a single Tdap dose for persons 11 to 18 years (preferably at 11 to 12 years), a single Tdap dose for adults 19 years or older who have never received Tdap, Tdap during every pregnancy, and a Td or Tdap booster every 10 years or for tetanus prophylaxis in wound management when at least 5 years have passed since the last tetanus toxoid-containing vaccine. Combination vaccines (Pediarix, Pentacel, Vaxelis, Kinrix and Quadracel) may be used as alternatives when given per FDA labeling and ACIP recommendations.
Aetna considers palivizumab (Synagis) medically necessary for commercial medical plans for up to 5 doses per RSV season to prevent serious lower respiratory tract disease caused by RSV, when a member has a qualifying diagnosis such as prematurity, chronic lung disease of prematurity, hemodynamically significant congenital heart disease, cystic fibrosis or profound immunocompromise and the associated criteria are met. Palivizumab is excluded for members who have received nirsevimab-alip (Beyfortus) in the same RSV season. The American Academy of Pediatrics stated that in July 2025 it no longer routinely recommends using Synagis.
Aetna considers orthopoxvirus vaccines medically necessary for the listed smallpox and mpox indications when the policy criteria are met, and routine smallpox vaccination of the general population is not recommended. Listed smallpox indications are pre-exposure vaccination for research laboratory personnel working with orthopoxviruses, clinical laboratory personnel performing diagnostic testing for orthopoxviruses, designated response team members at risk for occupational exposure, and healthcare personnel who administer ACAM2000 or care for persons infected with orthopoxviruses, along with JYNNEOS boosters for ongoing occupational exposure and post-exposure vaccination during a public health response. Listed mpox indications are pre-exposure vaccination for persons with known or presumed exposure to mpox virus or a sex partner diagnosed with mpox in the previous 14 days, and post-exposure JYNNEOS vaccination for persons with known or presumed exposure to mpox virus.
Cancer vaccines are considered experimental, investigational, or unproven because their safety and effectiveness have not been established. The listed items are the helper multi-peptide (6MHP) vaccine for metastatic melanoma, HLA-A24-binding peptide vaccines for gastric cancer, the melanoma vaccine (also known as Theraccine or Oncophage) for any indication, the p16(INK4a)-based peptide vaccine for human papillomavirus-associated cancers, the p62 DNA vaccine (Elenagen) for solid tumors, and whole cancer stem cell-based vaccines used as an adjuvant strategy for the surgical management of solid tumors. The clinical evidence is stated as not sufficient to permit conclusions on health outcome effects of tumor-associated antigenic peptide-based vaccine therapy for acute myeloid leukemia, breast cancer, central nervous system cancers, colorectal cancer, gallbladder cancer, gastric cancer, glioma, head and neck cancer, hepatic cancer, lung cancer, oral squamous cell carcinoma, ovarian cancer and pancreatic cancer.
Aetna's clinical policy bulletin covers onasemnogene abeparvovec (Zolgensma and Itvisma) for commercial medical plans and requires precertification of all Aetna participating providers and members in applicable plan designs. Aetna considers Zolgensma medically necessary as a single-dose intravenous infusion for spinal muscular atrophy (SMA) when the member is less than 2 years of age, has a genetically confirmed diagnosis with bi-allelic SMN1 variants and 3 or fewer copies of SMN2, and meets the other listed criteria, and considers Itvisma medically necessary as a single intrathecal dose for SMA when the member is 2 to less than 18 years of age, had onset of signs and symptoms at 6 months of age or older, and meets the other listed criteria. Aetna considers both products experimental, investigational, or unproven for all other indications, and considers repeat administration of onasemnogene abeparvovec experimental, investigational, or unproven.
Aetna considers anthrax vaccine medically necessary for pre-exposure prophylaxis in the groups the CDC's ACIP recommends, including decontamination personnel, laboratory workers who handle Bacillus anthracis, and military personnel deployed to high-risk areas. Anthrax vaccination for post-exposure prophylaxis is medically necessary after aerosolized exposure, while a single intravenous antitoxin dose is medically necessary for post-exposure prophylaxis only when antimicrobial drugs are not appropriate or not available. Anthrax vaccine and intravenous antitoxin drugs (raxibacumab, obiltoxaximab or AIGIV) are considered experimental, investigational, or unproven for all other indications.
CMS released new resources for the 2026 Interoperability Standards and Prior Authorization Proposed Rule, with comment period ending June 15. The update includes technical workflows, proposed metrics, and implementation guides for new prior authorization requirements and API standards.
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